diff --git a/src/liballoc/collections/linked_list.rs b/src/liballoc/collections/linked_list.rs
index a0c9263673d74..6ee22834a460e 100644
--- a/src/liballoc/collections/linked_list.rs
+++ b/src/liballoc/collections/linked_list.rs
@@ -808,7 +808,21 @@ impl<T> LinkedList<T> {
 #[stable(feature = "rust1", since = "1.0.0")]
 unsafe impl<#[may_dangle] T> Drop for LinkedList<T> {
     fn drop(&mut self) {
-        while let Some(_) = self.pop_front_node() {}
+        struct DropGuard<'a, T>(&'a mut LinkedList<T>);
+
+        impl<'a, T> Drop for DropGuard<'a, T> {
+            fn drop(&mut self) {
+                // Continue the same loop we do below. This only runs when a destructor has
+                // panicked. If another one panics this will abort.
+                while let Some(_) = self.0.pop_front_node() {}
+            }
+        }
+
+        while let Some(node) = self.pop_front_node() {
+            let guard = DropGuard(self);
+            drop(node);
+            mem::forget(guard);
+        }
     }
 }
 
diff --git a/src/liballoc/collections/vec_deque.rs b/src/liballoc/collections/vec_deque.rs
index 7795083e0580c..5ec69f73740c3 100644
--- a/src/liballoc/collections/vec_deque.rs
+++ b/src/liballoc/collections/vec_deque.rs
@@ -144,11 +144,23 @@ impl<T: Clone> Clone for VecDeque<T> {
 #[stable(feature = "rust1", since = "1.0.0")]
 unsafe impl<#[may_dangle] T> Drop for VecDeque<T> {
     fn drop(&mut self) {
+        /// Runs the destructor for all items in the slice when it gets dropped (normally or
+        /// during unwinding).
+        struct Dropper<'a, T>(&'a mut [T]);
+
+        impl<'a, T> Drop for Dropper<'a, T> {
+            fn drop(&mut self) {
+                unsafe {
+                    ptr::drop_in_place(self.0);
+                }
+            }
+        }
+
         let (front, back) = self.as_mut_slices();
         unsafe {
+            let _back_dropper = Dropper(back);
             // use drop for [T]
             ptr::drop_in_place(front);
-            ptr::drop_in_place(back);
         }
         // RawVec handles deallocation
     }
diff --git a/src/liballoc/tests/linked_list.rs b/src/liballoc/tests/linked_list.rs
index daa49c48c6a92..54a77d643cbe3 100644
--- a/src/liballoc/tests/linked_list.rs
+++ b/src/liballoc/tests/linked_list.rs
@@ -1,4 +1,5 @@
 use std::collections::LinkedList;
+use std::panic::catch_unwind;
 
 #[test]
 fn test_basic() {
@@ -529,3 +530,109 @@ fn drain_filter_complex() {
         assert_eq!(list.into_iter().collect::<Vec<_>>(), vec![1, 3, 5, 7, 9, 11, 13, 15, 17, 19]);
     }
 }
+
+
+#[test]
+fn test_drop() {
+    static mut DROPS: i32 = 0;
+    struct Elem;
+    impl Drop for Elem {
+        fn drop(&mut self) {
+            unsafe {
+                DROPS += 1;
+            }
+        }
+    }
+
+    let mut ring = LinkedList::new();
+    ring.push_back(Elem);
+    ring.push_front(Elem);
+    ring.push_back(Elem);
+    ring.push_front(Elem);
+    drop(ring);
+
+    assert_eq!(unsafe { DROPS }, 4);
+}
+
+#[test]
+fn test_drop_with_pop() {
+    static mut DROPS: i32 = 0;
+    struct Elem;
+    impl Drop for Elem {
+        fn drop(&mut self) {
+            unsafe {
+                DROPS += 1;
+            }
+        }
+    }
+
+    let mut ring = LinkedList::new();
+    ring.push_back(Elem);
+    ring.push_front(Elem);
+    ring.push_back(Elem);
+    ring.push_front(Elem);
+
+    drop(ring.pop_back());
+    drop(ring.pop_front());
+    assert_eq!(unsafe { DROPS }, 2);
+
+    drop(ring);
+    assert_eq!(unsafe { DROPS }, 4);
+}
+
+#[test]
+fn test_drop_clear() {
+    static mut DROPS: i32 = 0;
+    struct Elem;
+    impl Drop for Elem {
+        fn drop(&mut self) {
+            unsafe {
+                DROPS += 1;
+            }
+        }
+    }
+
+    let mut ring = LinkedList::new();
+    ring.push_back(Elem);
+    ring.push_front(Elem);
+    ring.push_back(Elem);
+    ring.push_front(Elem);
+    ring.clear();
+    assert_eq!(unsafe { DROPS }, 4);
+
+    drop(ring);
+    assert_eq!(unsafe { DROPS }, 4);
+}
+
+#[test]
+fn test_drop_panic() {
+    static mut DROPS: i32 = 0;
+
+    struct D(bool);
+
+    impl Drop for D {
+        fn drop(&mut self) {
+            unsafe {
+                DROPS += 1;
+            }
+
+            if self.0 {
+                panic!("panic in `drop`");
+            }
+        }
+    }
+
+    let mut q = LinkedList::new();
+    q.push_back(D(false));
+    q.push_back(D(false));
+    q.push_back(D(false));
+    q.push_back(D(false));
+    q.push_back(D(false));
+    q.push_front(D(false));
+    q.push_front(D(false));
+    q.push_front(D(true));
+
+    catch_unwind(move || drop(q)).ok();
+
+    assert_eq!(unsafe { DROPS }, 8);
+}
diff --git a/src/liballoc/tests/vec_deque.rs b/src/liballoc/tests/vec_deque.rs
index ebcc832017172..1ab3694a3ca61 100644
--- a/src/liballoc/tests/vec_deque.rs
+++ b/src/liballoc/tests/vec_deque.rs
@@ -2,6 +2,7 @@ use std::collections::TryReserveError::*;
 use std::collections::{vec_deque::Drain, VecDeque};
 use std::fmt::Debug;
 use std::mem::size_of;
+use std::panic::catch_unwind;
 use std::{isize, usize};
 
 use crate::hash;
@@ -709,6 +710,39 @@ fn test_drop_clear() {
     assert_eq!(unsafe { DROPS }, 4);
 }
 
+#[test]
+fn test_drop_panic() {
+    static mut DROPS: i32 = 0;
+
+    struct D(bool);
+
+    impl Drop for D {
+        fn drop(&mut self) {
+            unsafe {
+                DROPS += 1;
+            }
+
+            if self.0 {
+                panic!("panic in `drop`");
+            }
+        }
+    }
+
+    let mut q = VecDeque::new();
+    q.push_back(D(false));
+    q.push_back(D(false));
+    q.push_back(D(false));
+    q.push_back(D(false));
+    q.push_back(D(false));
+    q.push_front(D(false));
+    q.push_front(D(false));
+    q.push_front(D(true));
+
+    catch_unwind(move || drop(q)).ok();
+
+    assert_eq!(unsafe { DROPS }, 8);
+}
+
 #[test]
 fn test_reserve_grow() {
     // test growth path A
diff --git a/src/libcore/clone.rs b/src/libcore/clone.rs
index 6e7a46ba62aab..18f808638deac 100644
--- a/src/libcore/clone.rs
+++ b/src/libcore/clone.rs
@@ -195,7 +195,7 @@ mod impls {
         bool char
     }
 
-    #[stable(feature = "never_type", since = "1.41.0")]
+    #[unstable(feature = "never_type", issue = "35121")]
     impl Clone for ! {
         #[inline]
         fn clone(&self) -> Self {
diff --git a/src/libcore/cmp.rs b/src/libcore/cmp.rs
index fd4be02e20f4b..4aa52a7a390e3 100644
--- a/src/libcore/cmp.rs
+++ b/src/libcore/cmp.rs
@@ -1141,24 +1141,24 @@ mod impls {
 
     ord_impl! { char usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 
-    #[stable(feature = "never_type", since = "1.41.0")]
+    #[unstable(feature = "never_type", issue = "35121")]
     impl PartialEq for ! {
         fn eq(&self, _: &!) -> bool {
             *self
         }
     }
 
-    #[stable(feature = "never_type", since = "1.41.0")]
+    #[unstable(feature = "never_type", issue = "35121")]
     impl Eq for ! {}
 
-    #[stable(feature = "never_type", since = "1.41.0")]
+    #[unstable(feature = "never_type", issue = "35121")]
     impl PartialOrd for ! {
         fn partial_cmp(&self, _: &!) -> Option<Ordering> {
             *self
         }
     }
 
-    #[stable(feature = "never_type", since = "1.41.0")]
+    #[unstable(feature = "never_type", issue = "35121")]
     impl Ord for ! {
         fn cmp(&self, _: &!) -> Ordering {
             *self
diff --git a/src/libcore/convert/mod.rs b/src/libcore/convert/mod.rs
index 5414d9ac2344a..3329c8010e1c2 100644
--- a/src/libcore/convert/mod.rs
+++ b/src/libcore/convert/mod.rs
@@ -40,6 +40,8 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
+use crate::fmt;
+
 mod num;
 
 #[unstable(feature = "convert_float_to_int", issue = "67057")]
@@ -429,7 +431,9 @@ pub trait TryInto<T>: Sized {
 /// - `TryFrom<T> for U` implies [`TryInto`]`<U> for T`
 /// - [`try_from`] is reflexive, which means that `TryFrom<T> for T`
 /// is implemented and cannot fail -- the associated `Error` type for
-/// calling `T::try_from()` on a value of type `T` is [`!`].
+/// calling `T::try_from()` on a value of type `T` is [`Infallible`].
+/// When the [`!`] type is stabilized [`Infallible`] and [`!`] will be
+/// equivalent.
 ///
 /// `TryFrom<T>` can be implemented as follows:
 ///
@@ -478,6 +482,7 @@ pub trait TryInto<T>: Sized {
 /// [`TryInto`]: trait.TryInto.html
 /// [`i32::MAX`]: ../../std/i32/constant.MAX.html
 /// [`!`]: ../../std/primitive.never.html
+/// [`Infallible`]: enum.Infallible.html
 #[stable(feature = "try_from", since = "1.34.0")]
 pub trait TryFrom<T>: Sized {
     /// The type returned in the event of a conversion error.
@@ -633,9 +638,9 @@ impl AsRef<str> for str {
 // THE NO-ERROR ERROR TYPE
 ////////////////////////////////////////////////////////////////////////////////
 
-/// A type alias for [the `!` “never” type][never].
+/// The error type for errors that can never happen.
 ///
-/// `Infallible` represents types of errors that can never happen since `!` has no valid values.
+/// Since this enum has no variant, a value of this type can never actually exist.
 /// This can be useful for generic APIs that use [`Result`] and parameterize the error type,
 /// to indicate that the result is always [`Ok`].
 ///
@@ -652,10 +657,33 @@ impl AsRef<str> for str {
 /// }
 /// ```
 ///
-/// # Eventual deprecation
+/// # Future compatibility
+///
+/// This enum has the same role as [the `!` “never” type][never],
+/// which is unstable in this version of Rust.
+/// When `!` is stabilized, we plan to make `Infallible` a type alias to it:
+///
+/// ```ignore (illustrates future std change)
+/// pub type Infallible = !;
+/// ```
+///
+/// … and eventually deprecate `Infallible`.
+///
+///
+/// However there is one case where `!` syntax can be used
+/// before `!` is stabilized as a full-fleged type: in the position of a function’s return type.
+/// Specifically, it is possible implementations for two different function pointer types:
+///
+/// ```
+/// trait MyTrait {}
+/// impl MyTrait for fn() -> ! {}
+/// impl MyTrait for fn() -> std::convert::Infallible {}
+/// ```
 ///
-/// Previously, `Infallible` was defined as `enum Infallible {}`.
-/// Now that it is merely a type alias to `!`, we will eventually deprecate `Infallible`.
+/// With `Infallible` being an enum, this code is valid.
+/// However when `Infallible` becomes an alias for the never type,
+/// the two `impl`s will start to overlap
+/// and therefore will be disallowed by the language’s trait coherence rules.
 ///
 /// [`Ok`]: ../result/enum.Result.html#variant.Ok
 /// [`Result`]: ../result/enum.Result.html
@@ -663,4 +691,57 @@ impl AsRef<str> for str {
 /// [`Into`]: trait.Into.html
 /// [never]: ../../std/primitive.never.html
 #[stable(feature = "convert_infallible", since = "1.34.0")]
-pub type Infallible = !;
+#[derive(Copy)]
+pub enum Infallible {}
+
+#[stable(feature = "convert_infallible", since = "1.34.0")]
+impl Clone for Infallible {
+    fn clone(&self) -> Infallible {
+        match *self {}
+    }
+}
+
+#[stable(feature = "convert_infallible", since = "1.34.0")]
+impl fmt::Debug for Infallible {
+    fn fmt(&self, _: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match *self {}
+    }
+}
+
+#[stable(feature = "convert_infallible", since = "1.34.0")]
+impl fmt::Display for Infallible {
+    fn fmt(&self, _: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match *self {}
+    }
+}
+
+#[stable(feature = "convert_infallible", since = "1.34.0")]
+impl PartialEq for Infallible {
+    fn eq(&self, _: &Infallible) -> bool {
+        match *self {}
+    }
+}
+
+#[stable(feature = "convert_infallible", since = "1.34.0")]
+impl Eq for Infallible {}
+
+#[stable(feature = "convert_infallible", since = "1.34.0")]
+impl PartialOrd for Infallible {
+    fn partial_cmp(&self, _other: &Self) -> Option<crate::cmp::Ordering> {
+        match *self {}
+    }
+}
+
+#[stable(feature = "convert_infallible", since = "1.34.0")]
+impl Ord for Infallible {
+    fn cmp(&self, _other: &Self) -> crate::cmp::Ordering {
+        match *self {}
+    }
+}
+
+#[stable(feature = "convert_infallible", since = "1.34.0")]
+impl From<!> for Infallible {
+    fn from(x: !) -> Self {
+        x
+    }
+}
diff --git a/src/libcore/fmt/mod.rs b/src/libcore/fmt/mod.rs
index e2f49ee25a756..223f91d909b34 100644
--- a/src/libcore/fmt/mod.rs
+++ b/src/libcore/fmt/mod.rs
@@ -1940,14 +1940,14 @@ macro_rules! fmt_refs {
 
 fmt_refs! { Debug, Display, Octal, Binary, LowerHex, UpperHex, LowerExp, UpperExp }
 
-#[stable(feature = "never_type", since = "1.41.0")]
+#[unstable(feature = "never_type", issue = "35121")]
 impl Debug for ! {
     fn fmt(&self, _: &mut Formatter<'_>) -> Result {
         *self
     }
 }
 
-#[stable(feature = "never_type", since = "1.41.0")]
+#[unstable(feature = "never_type", issue = "35121")]
 impl Display for ! {
     fn fmt(&self, _: &mut Formatter<'_>) -> Result {
         *self
diff --git a/src/libcore/lib.rs b/src/libcore/lib.rs
index 8a514f1e78e80..8412e79aa333d 100644
--- a/src/libcore/lib.rs
+++ b/src/libcore/lib.rs
@@ -87,7 +87,7 @@
 #![feature(iter_once_with)]
 #![feature(lang_items)]
 #![feature(link_llvm_intrinsics)]
-#![cfg_attr(bootstrap, feature(never_type))]
+#![feature(never_type)]
 #![feature(nll)]
 #![feature(exhaustive_patterns)]
 #![feature(no_core)]
diff --git a/src/libcore/marker.rs b/src/libcore/marker.rs
index 288017b7ca53e..2db55508ad546 100644
--- a/src/libcore/marker.rs
+++ b/src/libcore/marker.rs
@@ -776,7 +776,7 @@ mod copy_impls {
         bool char
     }
 
-    #[stable(feature = "never_type", since = "1.41.0")]
+    #[unstable(feature = "never_type", issue = "35121")]
     impl Copy for ! {}
 
     #[stable(feature = "rust1", since = "1.0.0")]
diff --git a/src/libcore/num/mod.rs b/src/libcore/num/mod.rs
index d1f518d52dd72..00447a7d532f1 100644
--- a/src/libcore/num/mod.rs
+++ b/src/libcore/num/mod.rs
@@ -4,6 +4,7 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
+use crate::convert::Infallible;
 use crate::fmt;
 use crate::intrinsics;
 use crate::mem;
@@ -4724,8 +4725,18 @@ impl fmt::Display for TryFromIntError {
 }
 
 #[stable(feature = "try_from", since = "1.34.0")]
+impl From<Infallible> for TryFromIntError {
+    fn from(x: Infallible) -> TryFromIntError {
+        match x {}
+    }
+}
+
+#[unstable(feature = "never_type", issue = "35121")]
 impl From<!> for TryFromIntError {
     fn from(never: !) -> TryFromIntError {
+        // Match rather than coerce to make sure that code like
+        // `From<Infallible> for TryFromIntError` above will keep working
+        // when `Infallible` becomes an alias to `!`.
         match never {}
     }
 }
diff --git a/src/librustc/lib.rs b/src/librustc/lib.rs
index 24b87ffc80c2a..641e6a4f61489 100644
--- a/src/librustc/lib.rs
+++ b/src/librustc/lib.rs
@@ -37,7 +37,7 @@
 #![feature(core_intrinsics)]
 #![feature(drain_filter)]
 #![cfg_attr(windows, feature(libc))]
-#![cfg_attr(bootstrap, feature(never_type))]
+#![feature(never_type)]
 #![feature(exhaustive_patterns)]
 #![feature(overlapping_marker_traits)]
 #![feature(extern_types)]
diff --git a/src/librustc_codegen_utils/lib.rs b/src/librustc_codegen_utils/lib.rs
index f2739a3b30c92..fb2099e71a31a 100644
--- a/src/librustc_codegen_utils/lib.rs
+++ b/src/librustc_codegen_utils/lib.rs
@@ -8,7 +8,7 @@
 #![feature(box_patterns)]
 #![feature(box_syntax)]
 #![feature(core_intrinsics)]
-#![cfg_attr(bootstrap, feature(never_type))]
+#![feature(never_type)]
 #![feature(nll)]
 #![feature(in_band_lifetimes)]
 
diff --git a/src/librustc_error_codes/error_codes/E0725.md b/src/librustc_error_codes/error_codes/E0725.md
index b96a5e694dfc0..9bd321e5f82d6 100644
--- a/src/librustc_error_codes/error_codes/E0725.md
+++ b/src/librustc_error_codes/error_codes/E0725.md
@@ -4,8 +4,8 @@ command line flags.
 Erroneous code example:
 
 ```ignore (can't specify compiler flags from doctests)
-#![feature(specialization)] // error: the feature `specialization` is not in
-                            // the list of allowed features
+#![feature(never_type)] // error: the feature `never_type` is not in
+                        // the list of allowed features
 ```
 
 Delete the offending feature attribute, or add it to the list of allowed
diff --git a/src/librustc_feature/accepted.rs b/src/librustc_feature/accepted.rs
index fec5a7f1a4501..3f294dc02ed6f 100644
--- a/src/librustc_feature/accepted.rs
+++ b/src/librustc_feature/accepted.rs
@@ -253,8 +253,6 @@ declare_features! (
     (accepted, const_constructor, "1.40.0", Some(61456), None),
     /// Allows the use of `#[cfg(doctest)]`, set when rustdoc is collecting doctests.
     (accepted, cfg_doctest, "1.40.0", Some(62210), None),
-    /// Allows the `!` type. Does not imply 'exhaustive_patterns' any more.
-    (accepted, never_type, "1.41.0", Some(35121), None),
     /// Allows relaxing the coherence rules such that
     /// `impl<T> ForeignTrait<LocalType> for ForeignType<T>` is permitted.
     (accepted, re_rebalance_coherence, "1.41.0", Some(55437), None),
diff --git a/src/librustc_feature/active.rs b/src/librustc_feature/active.rs
index 363621b3ca436..c0dfed99d3bfc 100644
--- a/src/librustc_feature/active.rs
+++ b/src/librustc_feature/active.rs
@@ -307,6 +307,9 @@ declare_features! (
     /// Allows `X..Y` patterns.
     (active, exclusive_range_pattern, "1.11.0", Some(37854), None),
 
+    /// Allows the `!` type. Does not imply 'exhaustive_patterns' (below) any more.
+    (active, never_type, "1.13.0", Some(35121), None),
+
     /// Allows exhaustive pattern matching on types that contain uninhabited types.
     (active, exhaustive_patterns, "1.13.0", Some(51085), None),
 
diff --git a/src/librustc_mir/borrow_check/diagnostics/move_errors.rs b/src/librustc_mir/borrow_check/diagnostics/move_errors.rs
index 938836db9ae4b..cc634101f0adf 100644
--- a/src/librustc_mir/borrow_check/diagnostics/move_errors.rs
+++ b/src/librustc_mir/borrow_check/diagnostics/move_errors.rs
@@ -223,18 +223,24 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
 
     fn report(&mut self, error: GroupedMoveError<'tcx>) {
         let (mut err, err_span) = {
-            let (span, original_path, kind): (Span, &Place<'tcx>, &IllegalMoveOriginKind<'_>) =
+            let (span, use_spans, original_path, kind,):
+            (
+                Span,
+                Option<UseSpans>,
+                &Place<'tcx>,
+                &IllegalMoveOriginKind<'_>,
+            ) =
                 match error {
                     GroupedMoveError::MovesFromPlace { span, ref original_path, ref kind, .. } |
                     GroupedMoveError::MovesFromValue { span, ref original_path, ref kind, .. } => {
-                        (span, original_path, kind)
+                        (span, None, original_path, kind)
                     }
                     GroupedMoveError::OtherIllegalMove {
                         use_spans,
                         ref original_path,
                         ref kind
                     } => {
-                        (use_spans.args_or_use(), original_path, kind)
+                        (use_spans.args_or_use(), Some(use_spans), original_path, kind)
                     },
                 };
             debug!("report: original_path={:?} span={:?}, kind={:?} \
@@ -250,6 +256,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                             original_path,
                             target_place,
                             span,
+                            use_spans,
                         )
                     }
                     IllegalMoveOriginKind::InteriorOfTypeWithDestructor { container_ty: ty } => {
@@ -296,6 +303,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         move_place: &Place<'tcx>,
         deref_target_place: &Place<'tcx>,
         span: Span,
+        use_spans: Option<UseSpans>,
     ) -> DiagnosticBuilder<'a> {
         // Inspect the type of the content behind the
         // borrow to provide feedback about why this
@@ -416,7 +424,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         if let Ok(snippet) = self.infcx.tcx.sess.source_map().span_to_snippet(span) {
             let is_option = move_ty.starts_with("std::option::Option");
             let is_result = move_ty.starts_with("std::result::Result");
-            if is_option || is_result {
+            if (is_option || is_result) && use_spans.map_or(true, |v| !v.for_closure()) {
                 err.span_suggestion(
                     span,
                     &format!("consider borrowing the `{}`'s content", if is_option {
diff --git a/src/librustc_mir/lib.rs b/src/librustc_mir/lib.rs
index 42b72b64f8a30..f6b3c5b8e5e82 100644
--- a/src/librustc_mir/lib.rs
+++ b/src/librustc_mir/lib.rs
@@ -18,7 +18,7 @@ Rust MIR: a lowered representation of Rust. Also: an experiment!
 #![feature(drain_filter)]
 #![feature(exhaustive_patterns)]
 #![feature(iter_order_by)]
-#![cfg_attr(bootstrap, feature(never_type))]
+#![feature(never_type)]
 #![feature(specialization)]
 #![feature(try_trait)]
 #![feature(unicode_internals)]
diff --git a/src/librustc_mir/transform/qualify_min_const_fn.rs b/src/librustc_mir/transform/qualify_min_const_fn.rs
index cf2e1306dc44b..1c95155e7ff1c 100644
--- a/src/librustc_mir/transform/qualify_min_const_fn.rs
+++ b/src/librustc_mir/transform/qualify_min_const_fn.rs
@@ -80,7 +80,7 @@ fn check_ty(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, span: Span, fn_def_id: DefId) -> Mc
     for ty in ty.walk() {
         match ty.kind {
             ty::Ref(_, _, hir::Mutability::Mutable) => {
-                if !tcx.features().const_mut_refs {
+                if !feature_allowed(tcx, fn_def_id, sym::const_mut_refs) {
                     return Err((
                         span,
                         "mutable references in const fn are unstable".into(),
@@ -220,7 +220,7 @@ fn check_statement(
         }
 
         | StatementKind::FakeRead(FakeReadCause::ForMatchedPlace, _)
-        if !tcx.features().const_if_match
+        if !feature_allowed(tcx, def_id, sym::const_if_match)
         => {
             Err((span, "loops and conditional expressions are not stable in const fn".into()))
         }
@@ -272,7 +272,7 @@ fn check_place(
     while let &[ref proj_base @ .., elem] = cursor {
         cursor = proj_base;
         match elem {
-            ProjectionElem::Downcast(..) if !tcx.features().const_if_match
+            ProjectionElem::Downcast(..) if !feature_allowed(tcx, def_id, sym::const_if_match)
                 => return Err((span, "`match` or `if let` in `const fn` is unstable".into())),
             ProjectionElem::Downcast(_symbol, _variant_index) => {}
 
@@ -329,7 +329,7 @@ fn check_terminator(
 
         | TerminatorKind::FalseEdges { .. }
         | TerminatorKind::SwitchInt { .. }
-        if !tcx.features().const_if_match
+        if !feature_allowed(tcx, def_id, sym::const_if_match)
         => Err((
             span,
             "loops and conditional expressions are not stable in const fn".into(),
@@ -341,7 +341,7 @@ fn check_terminator(
         }
 
         // FIXME(ecstaticmorse): We probably want to allow `Unreachable` unconditionally.
-        TerminatorKind::Unreachable if tcx.features().const_if_match => Ok(()),
+        TerminatorKind::Unreachable if feature_allowed(tcx, def_id, sym::const_if_match) => Ok(()),
 
         | TerminatorKind::Abort | TerminatorKind::Unreachable => {
             Err((span, "const fn with unreachable code is not stable".into()))
diff --git a/src/librustc_target/spec/i686_unknown_dragonfly.rs b/src/librustc_target/spec/i686_unknown_dragonfly.rs
deleted file mode 100644
index 20315e7145c73..0000000000000
--- a/src/librustc_target/spec/i686_unknown_dragonfly.rs
+++ /dev/null
@@ -1,23 +0,0 @@
-use crate::spec::{LinkerFlavor, Target, TargetResult};
-
-pub fn target() -> TargetResult {
-    let mut base = super::dragonfly_base::opts();
-    base.cpu = "pentium4".to_string();
-    base.max_atomic_width = Some(64);
-    base.pre_link_args.get_mut(&LinkerFlavor::Gcc).unwrap().push("-m32".to_string());
-    base.stack_probes = true;
-
-    Ok(Target {
-        llvm_target: "i686-unknown-dragonfly".to_string(),
-        target_endian: "little".to_string(),
-        target_pointer_width: "32".to_string(),
-        target_c_int_width: "32".to_string(),
-        data_layout: "e-m:e-p:32:32-f64:32:64-f80:32-n8:16:32-S128".to_string(),
-        arch: "x86".to_string(),
-        target_os: "dragonfly".to_string(),
-        target_env: String::new(),
-        target_vendor: "unknown".to_string(),
-        linker_flavor: LinkerFlavor::Gcc,
-        options: base,
-    })
-}
diff --git a/src/librustc_target/spec/mod.rs b/src/librustc_target/spec/mod.rs
index 693cf75e8fd64..34b321d38f0f6 100644
--- a/src/librustc_target/spec/mod.rs
+++ b/src/librustc_target/spec/mod.rs
@@ -398,7 +398,6 @@ supported_targets! {
     ("powerpc64-unknown-freebsd", powerpc64_unknown_freebsd),
     ("x86_64-unknown-freebsd", x86_64_unknown_freebsd),
 
-    ("i686-unknown-dragonfly", i686_unknown_dragonfly),
     ("x86_64-unknown-dragonfly", x86_64_unknown_dragonfly),
 
     ("aarch64-unknown-openbsd", aarch64_unknown_openbsd),
diff --git a/src/librustc_typeck/lib.rs b/src/librustc_typeck/lib.rs
index 6a6294b6f8798..c6c9703e92c92 100644
--- a/src/librustc_typeck/lib.rs
+++ b/src/librustc_typeck/lib.rs
@@ -67,7 +67,7 @@ This API is completely unstable and subject to change.
 #![feature(in_band_lifetimes)]
 #![feature(nll)]
 #![feature(slice_patterns)]
-#![cfg_attr(bootstrap, feature(never_type))]
+#![feature(never_type)]
 
 #![recursion_limit="256"]
 
diff --git a/src/librustdoc/lib.rs b/src/librustdoc/lib.rs
index a4be3dee938ed..8fed351c7a394 100644
--- a/src/librustdoc/lib.rs
+++ b/src/librustdoc/lib.rs
@@ -14,7 +14,7 @@
 #![feature(crate_visibility_modifier)]
 #![feature(const_fn)]
 #![feature(drain_filter)]
-#![cfg_attr(bootstrap, feature(never_type))]
+#![feature(never_type)]
 #![feature(unicode_internals)]
 
 #![recursion_limit="256"]
diff --git a/src/libserialize/lib.rs b/src/libserialize/lib.rs
index 13d83337f5f6f..e45d56c320cd8 100644
--- a/src/libserialize/lib.rs
+++ b/src/libserialize/lib.rs
@@ -11,7 +11,7 @@ Core encoding and decoding interfaces.
 #![feature(box_syntax)]
 #![feature(core_intrinsics)]
 #![feature(specialization)]
-#![cfg_attr(bootstrap, feature(never_type))]
+#![feature(never_type)]
 #![feature(nll)]
 #![feature(associated_type_bounds)]
 #![cfg_attr(test, feature(test))]
diff --git a/src/libstd/error.rs b/src/libstd/error.rs
index ec1c444bcf8c8..d4c4cb9c3b997 100644
--- a/src/libstd/error.rs
+++ b/src/libstd/error.rs
@@ -465,7 +465,7 @@ impl<'a> From<Cow<'a, str>> for Box<dyn Error> {
     }
 }
 
-#[stable(feature = "never_type", since = "1.41.0")]
+#[unstable(feature = "never_type", issue = "35121")]
 impl Error for ! {
     fn description(&self) -> &str { *self }
 }
@@ -551,6 +551,13 @@ impl Error for string::FromUtf16Error {
     }
 }
 
+#[stable(feature = "str_parse_error2", since = "1.8.0")]
+impl Error for string::ParseError {
+    fn description(&self) -> &str {
+        match *self {}
+    }
+}
+
 #[stable(feature = "decode_utf16", since = "1.9.0")]
 impl Error for char::DecodeUtf16Error {
     fn description(&self) -> &str {
diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index 1dbb0c6ec8310..6128c1d46ae3b 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -281,7 +281,7 @@
 #![feature(maybe_uninit_ref)]
 #![feature(maybe_uninit_slice)]
 #![feature(needs_panic_runtime)]
-#![cfg_attr(bootstrap, feature(never_type))]
+#![feature(never_type)]
 #![feature(nll)]
 #![cfg_attr(bootstrap, feature(on_unimplemented))]
 #![feature(optin_builtin_traits)]
diff --git a/src/libstd/primitive_docs.rs b/src/libstd/primitive_docs.rs
index b4495588c9949..a72951c034610 100644
--- a/src/libstd/primitive_docs.rs
+++ b/src/libstd/primitive_docs.rs
@@ -71,6 +71,7 @@ mod prim_bool { }
 /// write:
 ///
 /// ```
+/// #![feature(never_type)]
 /// # fn foo() -> u32 {
 /// let x: ! = {
 ///     return 123
@@ -200,6 +201,7 @@ mod prim_bool { }
 /// for example:
 ///
 /// ```
+/// #![feature(never_type)]
 /// # use std::fmt;
 /// # trait Debug {
 /// # fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result;
@@ -237,7 +239,7 @@ mod prim_bool { }
 /// [`Default`]: default/trait.Default.html
 /// [`default()`]: default/trait.Default.html#tymethod.default
 ///
-#[stable(feature = "never_type", since = "1.41.0")]
+#[unstable(feature = "never_type", issue = "35121")]
 mod prim_never { }
 
 #[doc(primitive = "char")]
diff --git a/src/libsyntax/feature_gate/check.rs b/src/libsyntax/feature_gate/check.rs
index 3d2c3b1d4f901..99d89183e5b0d 100644
--- a/src/libsyntax/feature_gate/check.rs
+++ b/src/libsyntax/feature_gate/check.rs
@@ -464,11 +464,25 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
             ast::TyKind::BareFn(ref bare_fn_ty) => {
                 self.check_extern(bare_fn_ty.ext);
             }
+            ast::TyKind::Never => {
+                gate_feature_post!(&self, never_type, ty.span,
+                                   "The `!` type is experimental");
+            }
             _ => {}
         }
         visit::walk_ty(self, ty)
     }
 
+    fn visit_fn_ret_ty(&mut self, ret_ty: &'a ast::FunctionRetTy) {
+        if let ast::FunctionRetTy::Ty(ref output_ty) = *ret_ty {
+            if let ast::TyKind::Never = output_ty.kind {
+                // Do nothing.
+            } else {
+                self.visit_ty(output_ty)
+            }
+        }
+    }
+
     fn visit_expr(&mut self, e: &'a ast::Expr) {
         match e.kind {
             ast::ExprKind::Box(_) => {
@@ -499,6 +513,10 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
         visit::walk_expr(self, e)
     }
 
+    fn visit_arm(&mut self, arm: &'a ast::Arm) {
+        visit::walk_arm(self, arm)
+    }
+
     fn visit_pat(&mut self, pattern: &'a ast::Pat) {
         match &pattern.kind {
             PatKind::Slice(pats) => {
diff --git a/src/libsyntax_expand/mbe/macro_parser.rs b/src/libsyntax_expand/mbe/macro_parser.rs
index bf7960f90660a..1e2f3f9d1e53e 100644
--- a/src/libsyntax_expand/mbe/macro_parser.rs
+++ b/src/libsyntax_expand/mbe/macro_parser.rs
@@ -83,7 +83,7 @@ use syntax::print::pprust;
 use syntax::sess::ParseSess;
 use syntax::symbol::{kw, sym, Symbol};
 use syntax::token::{self, DocComment, Nonterminal, Token};
-use syntax::tokenstream::{DelimSpan, TokenStream};
+use syntax::tokenstream::TokenStream;
 
 use errors::{PResult, FatalError};
 use smallvec::{smallvec, SmallVec};
@@ -164,11 +164,6 @@ struct MatcherPos<'root, 'tt> {
     /// The position of the "dot" in this matcher
     idx: usize,
 
-    /// The first span of source that the beginning of this matcher corresponds to. In other
-    /// words, the token in the source whose span is `sp_open` is matched against the first token of
-    /// the matcher.
-    sp_open: Span,
-
     /// For each named metavar in the matcher, we keep track of token trees matched against the
     /// metavar by the black box parser. In particular, there may be more than one match per
     /// metavar if we are in a repetition (each repetition matches each of the variables).
@@ -307,8 +302,8 @@ fn create_matches(len: usize) -> Box<[Lrc<NamedMatchVec>]> {
 }
 
 /// Generates the top-level matcher position in which the "dot" is before the first token of the
-/// matcher `ms` and we are going to start matching at the span `open` in the source.
-fn initial_matcher_pos<'root, 'tt>(ms: &'tt [TokenTree], open: Span) -> MatcherPos<'root, 'tt> {
+/// matcher `ms`.
+fn initial_matcher_pos<'root, 'tt>(ms: &'tt [TokenTree]) -> MatcherPos<'root, 'tt> {
     let match_idx_hi = count_names(ms);
     let matches = create_matches(match_idx_hi);
     MatcherPos {
@@ -316,8 +311,6 @@ fn initial_matcher_pos<'root, 'tt>(ms: &'tt [TokenTree], open: Span) -> MatcherP
         top_elts: TtSeq(ms), // "elts" is an abbr. for "elements"
         // The "dot" is before the first token of the matcher
         idx: 0,
-        // We start matching at the span `open` in the source code
-        sp_open: open,
 
         // Initialize `matches` to a bunch of empty `Vec`s -- one for each metavar in `top_elts`.
         // `match_lo` for `top_elts` is 0 and `match_hi` is `matches.len()`. `match_cur` is 0 since
@@ -355,7 +348,7 @@ fn initial_matcher_pos<'root, 'tt>(ms: &'tt [TokenTree], open: Span) -> MatcherP
 /// token tree it was derived from.
 #[derive(Debug, Clone)]
 crate enum NamedMatch {
-    MatchedSeq(Lrc<NamedMatchVec>, DelimSpan),
+    MatchedSeq(Lrc<NamedMatchVec>),
     MatchedNonterminal(Lrc<Nonterminal>),
 }
 
@@ -497,8 +490,7 @@ fn inner_parse_loop<'root, 'tt>(
                     // Add matches from this repetition to the `matches` of `up`
                     for idx in item.match_lo..item.match_hi {
                         let sub = item.matches[idx].clone();
-                        let span = DelimSpan::from_pair(item.sp_open, token.span);
-                        new_pos.push_match(idx, MatchedSeq(sub, span));
+                        new_pos.push_match(idx, MatchedSeq(sub));
                     }
 
                     // Move the "dot" past the repetition in `up`
@@ -552,7 +544,7 @@ fn inner_parse_loop<'root, 'tt>(
                         new_item.match_cur += seq.num_captures;
                         new_item.idx += 1;
                         for idx in item.match_cur..item.match_cur + seq.num_captures {
-                            new_item.push_match(idx, MatchedSeq(Lrc::new(smallvec![]), sp));
+                            new_item.push_match(idx, MatchedSeq(Lrc::new(smallvec![])));
                         }
                         cur_items.push(new_item);
                     }
@@ -568,7 +560,6 @@ fn inner_parse_loop<'root, 'tt>(
                         match_cur: item.match_cur,
                         match_hi: item.match_cur + seq.num_captures,
                         up: Some(item),
-                        sp_open: sp.open,
                         top_elts: Tt(TokenTree::Sequence(sp, seq)),
                     })));
                 }
@@ -663,7 +654,7 @@ pub(super) fn parse(
     //
     // This MatcherPos instance is allocated on the stack. All others -- and
     // there are frequently *no* others! -- are allocated on the heap.
-    let mut initial = initial_matcher_pos(ms, parser.token.span);
+    let mut initial = initial_matcher_pos(ms);
     let mut cur_items = smallvec![MatcherPosHandle::Ref(&mut initial)];
     let mut next_items = Vec::new();
 
diff --git a/src/libsyntax_expand/mbe/macro_rules.rs b/src/libsyntax_expand/mbe/macro_rules.rs
index e3c3655bcf882..2dd15872a9f0a 100644
--- a/src/libsyntax_expand/mbe/macro_rules.rs
+++ b/src/libsyntax_expand/mbe/macro_rules.rs
@@ -379,7 +379,7 @@ pub fn compile_declarative_macro(
 
     // Extract the arguments:
     let lhses = match argument_map[&lhs_nm] {
-        MatchedSeq(ref s, _) => s
+        MatchedSeq(ref s) => s
             .iter()
             .map(|m| {
                 if let MatchedNonterminal(ref nt) = *m {
@@ -402,7 +402,7 @@ pub fn compile_declarative_macro(
     };
 
     let rhses = match argument_map[&rhs_nm] {
-        MatchedSeq(ref s, _) => s
+        MatchedSeq(ref s) => s
             .iter()
             .map(|m| {
                 if let MatchedNonterminal(ref nt) = *m {
diff --git a/src/libsyntax_expand/mbe/transcribe.rs b/src/libsyntax_expand/mbe/transcribe.rs
index a1157667df1b4..0605f7ff36df7 100644
--- a/src/libsyntax_expand/mbe/transcribe.rs
+++ b/src/libsyntax_expand/mbe/transcribe.rs
@@ -299,7 +299,7 @@ fn lookup_cur_matched<'a>(
         for &(idx, _) in repeats {
             match matched {
                 MatchedNonterminal(_) => break,
-                MatchedSeq(ref ads, _) => matched = ads.get(idx).unwrap(),
+                MatchedSeq(ref ads) => matched = ads.get(idx).unwrap(),
             }
         }
 
@@ -382,7 +382,7 @@ fn lockstep_iter_size(
             match lookup_cur_matched(name, interpolations, repeats) {
                 Some(matched) => match matched {
                     MatchedNonterminal(_) => LockstepIterSize::Unconstrained,
-                    MatchedSeq(ref ads, _) => LockstepIterSize::Constraint(ads.len(), name),
+                    MatchedSeq(ref ads) => LockstepIterSize::Constraint(ads.len(), name),
                 },
                 _ => LockstepIterSize::Unconstrained,
             }
diff --git a/src/test/codegen/enum-debug-niche-2.rs b/src/test/codegen/enum-debug-niche-2.rs
index 7e00dc5463f68..0f17976ef4965 100644
--- a/src/test/codegen/enum-debug-niche-2.rs
+++ b/src/test/codegen/enum-debug-niche-2.rs
@@ -12,6 +12,8 @@
 // CHECK: {{.*}}DIDerivedType{{.*}}tag: DW_TAG_member,{{.*}}name: "Placeholder",{{.*}}extraData: i64 4294967295{{[,)].*}}
 // CHECK: {{.*}}DIDerivedType{{.*}}tag: DW_TAG_member,{{.*}}name: "Error",{{.*}}extraData: i64 0{{[,)].*}}
 
+#![feature(never_type)]
+
 #[derive(Copy, Clone)]
 pub struct Entity {
     private: std::num::NonZeroU32,
diff --git a/src/test/mir-opt/retain-never-const.rs b/src/test/mir-opt/retain-never-const.rs
index 5d59b2f48429d..04394dcdf1334 100644
--- a/src/test/mir-opt/retain-never-const.rs
+++ b/src/test/mir-opt/retain-never-const.rs
@@ -5,6 +5,7 @@
 // compile-flags: --emit mir,link
 
 #![feature(const_panic)]
+#![feature(never_type)]
 
 struct PrintName<T>(T);
 
diff --git a/src/test/mir-opt/uninhabited-enum.rs b/src/test/mir-opt/uninhabited-enum.rs
index 409be8587cf0f..904a9c43c1bcc 100644
--- a/src/test/mir-opt/uninhabited-enum.rs
+++ b/src/test/mir-opt/uninhabited-enum.rs
@@ -1,3 +1,5 @@
+#![feature(never_type)]
+
 pub enum Void {}
 
 #[no_mangle]
diff --git a/src/test/ui/binding/empty-types-in-patterns.rs b/src/test/ui/binding/empty-types-in-patterns.rs
index 1864d4bb8205b..4271ffb7b1b4d 100644
--- a/src/test/ui/binding/empty-types-in-patterns.rs
+++ b/src/test/ui/binding/empty-types-in-patterns.rs
@@ -1,5 +1,5 @@
 // run-pass
-#![feature(never_type_fallback)]
+#![feature(never_type, never_type_fallback)]
 #![feature(exhaustive_patterns)]
 #![feature(slice_patterns)]
 #![allow(unreachable_patterns)]
diff --git a/src/test/ui/borrowck/assign-never-type.rs b/src/test/ui/borrowck/assign-never-type.rs
index 52b2e70d159a9..4f30ea1467023 100644
--- a/src/test/ui/borrowck/assign-never-type.rs
+++ b/src/test/ui/borrowck/assign-never-type.rs
@@ -2,6 +2,8 @@
 
 // check-pass
 
+#![feature(never_type)]
+
 pub fn main() {
     loop {
         match None {
diff --git a/src/test/ui/break-while-condition.rs b/src/test/ui/break-while-condition.rs
index 7aa5682b923a6..6064e6ab00235 100644
--- a/src/test/ui/break-while-condition.rs
+++ b/src/test/ui/break-while-condition.rs
@@ -1,3 +1,5 @@
+#![feature(never_type)]
+
 fn main() {
     // The `if false` expressions are simply to
     // make sure we don't avoid checking everything
diff --git a/src/test/ui/break-while-condition.stderr b/src/test/ui/break-while-condition.stderr
index bbc9f21edb06e..6960c4fd86735 100644
--- a/src/test/ui/break-while-condition.stderr
+++ b/src/test/ui/break-while-condition.stderr
@@ -1,5 +1,5 @@
 error[E0308]: mismatched types
-  --> $DIR/break-while-condition.rs:7:20
+  --> $DIR/break-while-condition.rs:9:20
    |
 LL |           let _: ! = {
    |  ____________________^
@@ -11,7 +11,7 @@ LL | |         };
            found unit type `()`
 
 error[E0308]: mismatched types
-  --> $DIR/break-while-condition.rs:14:13
+  --> $DIR/break-while-condition.rs:16:13
    |
 LL | /             while false {
 LL | |                 break
@@ -22,7 +22,7 @@ LL | |             }
            found unit type `()`
 
 error[E0308]: mismatched types
-  --> $DIR/break-while-condition.rs:22:13
+  --> $DIR/break-while-condition.rs:24:13
    |
 LL | /             while false {
 LL | |                 return
diff --git a/src/test/ui/coercion/coerce-issue-49593-box-never.rs b/src/test/ui/coercion/coerce-issue-49593-box-never.rs
index 55beb7c252895..0824ce8cd585b 100644
--- a/src/test/ui/coercion/coerce-issue-49593-box-never.rs
+++ b/src/test/ui/coercion/coerce-issue-49593-box-never.rs
@@ -1,5 +1,5 @@
 // check-pass
-#![feature(never_type_fallback)]
+#![feature(never_type, never_type_fallback)]
 #![allow(unreachable_code)]
 
 use std::error::Error;
diff --git a/src/test/ui/coercion/coerce-to-bang-cast.rs b/src/test/ui/coercion/coerce-to-bang-cast.rs
index ea1384a1dab55..8ef1948084654 100644
--- a/src/test/ui/coercion/coerce-to-bang-cast.rs
+++ b/src/test/ui/coercion/coerce-to-bang-cast.rs
@@ -1,3 +1,5 @@
+#![feature(never_type)]
+
 fn foo(x: usize, y: !, z: usize) { }
 
 fn cast_a() {
diff --git a/src/test/ui/coercion/coerce-to-bang-cast.stderr b/src/test/ui/coercion/coerce-to-bang-cast.stderr
index 0e17f32511f82..ff30ebc09c63a 100644
--- a/src/test/ui/coercion/coerce-to-bang-cast.stderr
+++ b/src/test/ui/coercion/coerce-to-bang-cast.stderr
@@ -1,5 +1,5 @@
 error[E0605]: non-primitive cast: `i32` as `!`
-  --> $DIR/coerce-to-bang-cast.rs:4:13
+  --> $DIR/coerce-to-bang-cast.rs:6:13
    |
 LL |     let y = {return; 22} as !;
    |             ^^^^^^^^^^^^^^^^^
@@ -7,7 +7,7 @@ LL |     let y = {return; 22} as !;
    = note: an `as` expression can only be used to convert between primitive types. Consider using the `From` trait
 
 error[E0605]: non-primitive cast: `i32` as `!`
-  --> $DIR/coerce-to-bang-cast.rs:9:13
+  --> $DIR/coerce-to-bang-cast.rs:11:13
    |
 LL |     let y = 22 as !;
    |             ^^^^^^^
diff --git a/src/test/ui/coercion/coerce-to-bang.rs b/src/test/ui/coercion/coerce-to-bang.rs
index d52f79fbb7a98..1e06934d09f9e 100644
--- a/src/test/ui/coercion/coerce-to-bang.rs
+++ b/src/test/ui/coercion/coerce-to-bang.rs
@@ -1,3 +1,5 @@
+#![feature(never_type)]
+
 fn foo(x: usize, y: !, z: usize) { }
 
 fn call_foo_a() {
diff --git a/src/test/ui/coercion/coerce-to-bang.stderr b/src/test/ui/coercion/coerce-to-bang.stderr
index ca42705973750..390aa7c692d18 100644
--- a/src/test/ui/coercion/coerce-to-bang.stderr
+++ b/src/test/ui/coercion/coerce-to-bang.stderr
@@ -1,5 +1,5 @@
 error[E0308]: mismatched types
-  --> $DIR/coerce-to-bang.rs:4:17
+  --> $DIR/coerce-to-bang.rs:6:17
    |
 LL |     foo(return, 22, 44);
    |                 ^^ expected `!`, found integer
@@ -8,7 +8,7 @@ LL |     foo(return, 22, 44);
               found type `{integer}`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-to-bang.rs:16:13
+  --> $DIR/coerce-to-bang.rs:18:13
    |
 LL |     foo(22, 44, return);
    |             ^^ expected `!`, found integer
@@ -17,7 +17,7 @@ LL |     foo(22, 44, return);
               found type `{integer}`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-to-bang.rs:24:12
+  --> $DIR/coerce-to-bang.rs:26:12
    |
 LL |     foo(a, b, c); // ... and hence a reference to `a` is expected to diverge.
    |            ^ expected `!`, found integer
@@ -26,7 +26,7 @@ LL |     foo(a, b, c); // ... and hence a reference to `a` is expected to diverg
               found type `{integer}`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-to-bang.rs:34:12
+  --> $DIR/coerce-to-bang.rs:36:12
    |
 LL |     foo(a, b, c);
    |            ^ expected `!`, found integer
@@ -35,7 +35,7 @@ LL |     foo(a, b, c);
               found type `{integer}`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-to-bang.rs:43:12
+  --> $DIR/coerce-to-bang.rs:45:12
    |
 LL |     foo(a, b, c);
    |            ^ expected `!`, found integer
@@ -44,7 +44,7 @@ LL |     foo(a, b, c);
               found type `{integer}`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-to-bang.rs:48:21
+  --> $DIR/coerce-to-bang.rs:50:21
    |
 LL |     let x: [!; 2] = [return, 22];
    |            ------   ^^^^^^^^^^^^ expected `!`, found integer
@@ -55,7 +55,7 @@ LL |     let x: [!; 2] = [return, 22];
               found array `[{integer}; 2]`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-to-bang.rs:53:22
+  --> $DIR/coerce-to-bang.rs:55:22
    |
 LL |     let x: [!; 2] = [22, return];
    |                      ^^ expected `!`, found integer
@@ -64,7 +64,7 @@ LL |     let x: [!; 2] = [22, return];
               found type `{integer}`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-to-bang.rs:58:37
+  --> $DIR/coerce-to-bang.rs:60:37
    |
 LL |     let x: (usize, !, usize) = (22, 44, 66);
    |                                     ^^ expected `!`, found integer
@@ -73,7 +73,7 @@ LL |     let x: (usize, !, usize) = (22, 44, 66);
               found type `{integer}`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-to-bang.rs:63:41
+  --> $DIR/coerce-to-bang.rs:65:41
    |
 LL |     let x: (usize, !, usize) = (return, 44, 66);
    |                                         ^^ expected `!`, found integer
@@ -82,7 +82,7 @@ LL |     let x: (usize, !, usize) = (return, 44, 66);
               found type `{integer}`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-to-bang.rs:74:37
+  --> $DIR/coerce-to-bang.rs:76:37
    |
 LL |     let x: (usize, !, usize) = (22, 44, return);
    |                                     ^^ expected `!`, found integer
diff --git a/src/test/ui/consts/const-eval/index-out-of-bounds-never-type.rs b/src/test/ui/consts/const-eval/index-out-of-bounds-never-type.rs
index 516ca4f3f77e0..f6ab0bd7dbed6 100644
--- a/src/test/ui/consts/const-eval/index-out-of-bounds-never-type.rs
+++ b/src/test/ui/consts/const-eval/index-out-of-bounds-never-type.rs
@@ -1,5 +1,6 @@
 // Regression test for #66975
 #![warn(const_err)]
+#![feature(never_type)]
 
 struct PrintName<T>(T);
 
diff --git a/src/test/ui/consts/const-eval/index-out-of-bounds-never-type.stderr b/src/test/ui/consts/const-eval/index-out-of-bounds-never-type.stderr
index e2bd8d0cc85ea..24830f7344c3b 100644
--- a/src/test/ui/consts/const-eval/index-out-of-bounds-never-type.stderr
+++ b/src/test/ui/consts/const-eval/index-out-of-bounds-never-type.stderr
@@ -1,5 +1,5 @@
 warning: any use of this value will cause an error
-  --> $DIR/index-out-of-bounds-never-type.rs:7:61
+  --> $DIR/index-out-of-bounds-never-type.rs:8:61
    |
 LL |     const VOID: ! = { let x = 0 * std::mem::size_of::<T>(); [][x] };
    |     --------------------------------------------------------^^^^^---
@@ -13,7 +13,7 @@ LL | #![warn(const_err)]
    |         ^^^^^^^^^
 
 error: erroneous constant encountered
-  --> $DIR/index-out-of-bounds-never-type.rs:12:13
+  --> $DIR/index-out-of-bounds-never-type.rs:13:13
    |
 LL |     let _ = PrintName::<T>::VOID;
    |             ^^^^^^^^^^^^^^^^^^^^
diff --git a/src/test/ui/consts/const-eval/panic-assoc-never-type.rs b/src/test/ui/consts/const-eval/panic-assoc-never-type.rs
index b39d9af5546f8..a7cbdb40ef108 100644
--- a/src/test/ui/consts/const-eval/panic-assoc-never-type.rs
+++ b/src/test/ui/consts/const-eval/panic-assoc-never-type.rs
@@ -1,6 +1,7 @@
 // Regression test for #66975
 #![warn(const_err)]
 #![feature(const_panic)]
+#![feature(never_type)]
 
 struct PrintName;
 
diff --git a/src/test/ui/consts/const-eval/panic-assoc-never-type.stderr b/src/test/ui/consts/const-eval/panic-assoc-never-type.stderr
index c07c8c65a2f20..e15952c20e493 100644
--- a/src/test/ui/consts/const-eval/panic-assoc-never-type.stderr
+++ b/src/test/ui/consts/const-eval/panic-assoc-never-type.stderr
@@ -1,10 +1,10 @@
 warning: any use of this value will cause an error
-  --> $DIR/panic-assoc-never-type.rs:8:21
+  --> $DIR/panic-assoc-never-type.rs:9:21
    |
 LL |     const VOID: ! = panic!();
    |     ----------------^^^^^^^^-
    |                     |
-   |                     the evaluated program panicked at 'explicit panic', $DIR/panic-assoc-never-type.rs:8:21
+   |                     the evaluated program panicked at 'explicit panic', $DIR/panic-assoc-never-type.rs:9:21
    |
 note: lint level defined here
   --> $DIR/panic-assoc-never-type.rs:2:9
@@ -14,7 +14,7 @@ LL | #![warn(const_err)]
    = note: this warning originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
 
 error[E0080]: erroneous constant used
-  --> $DIR/panic-assoc-never-type.rs:13:13
+  --> $DIR/panic-assoc-never-type.rs:14:13
    |
 LL |     let _ = PrintName::VOID;
    |             ^^^^^^^^^^^^^^^ referenced constant has errors
diff --git a/src/test/ui/consts/const-eval/panic-never-type.rs b/src/test/ui/consts/const-eval/panic-never-type.rs
index 42eabbf58470f..b1a7d8ae676a8 100644
--- a/src/test/ui/consts/const-eval/panic-never-type.rs
+++ b/src/test/ui/consts/const-eval/panic-never-type.rs
@@ -1,6 +1,7 @@
 // Regression test for #66975
 #![warn(const_err)]
 #![feature(const_panic)]
+#![feature(never_type)]
 
 const VOID: ! = panic!();
 //~^ WARN any use of this value will cause an error
diff --git a/src/test/ui/consts/const-eval/panic-never-type.stderr b/src/test/ui/consts/const-eval/panic-never-type.stderr
index 4fb11a61525f4..9e91fdf451415 100644
--- a/src/test/ui/consts/const-eval/panic-never-type.stderr
+++ b/src/test/ui/consts/const-eval/panic-never-type.stderr
@@ -1,10 +1,10 @@
 warning: any use of this value will cause an error
-  --> $DIR/panic-never-type.rs:5:17
+  --> $DIR/panic-never-type.rs:6:17
    |
 LL | const VOID: ! = panic!();
    | ----------------^^^^^^^^-
    |                 |
-   |                 the evaluated program panicked at 'explicit panic', $DIR/panic-never-type.rs:5:17
+   |                 the evaluated program panicked at 'explicit panic', $DIR/panic-never-type.rs:6:17
    |
 note: lint level defined here
   --> $DIR/panic-never-type.rs:2:9
@@ -14,7 +14,7 @@ LL | #![warn(const_err)]
    = note: this warning originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
 
 error[E0080]: erroneous constant used
-  --> $DIR/panic-never-type.rs:9:13
+  --> $DIR/panic-never-type.rs:10:13
    |
 LL |     let _ = VOID;
    |             ^^^^ referenced constant has errors
diff --git a/src/test/ui/consts/const-mut-refs/const_mut_refs.rs b/src/test/ui/consts/const-mut-refs/const_mut_refs.rs
index 99006a20b1bcb..33abfec02a87a 100644
--- a/src/test/ui/consts/const-mut-refs/const_mut_refs.rs
+++ b/src/test/ui/consts/const-mut-refs/const_mut_refs.rs
@@ -1,6 +1,7 @@
 // run-pass
 
 #![feature(const_mut_refs)]
+#![feature(const_fn)]
 
 struct Foo {
     x: usize
diff --git a/src/test/ui/consts/control-flow/basics.rs b/src/test/ui/consts/control-flow/basics.rs
index 8bd1929956fd3..b9ff040915863 100644
--- a/src/test/ui/consts/control-flow/basics.rs
+++ b/src/test/ui/consts/control-flow/basics.rs
@@ -4,6 +4,7 @@
 
 #![feature(const_panic)]
 #![feature(const_if_match)]
+#![feature(const_fn)]
 
 const X: u32 = 4;
 const Y: u32 = 5;
diff --git a/src/test/ui/consts/control-flow/exhaustive-c-like-enum-match.rs b/src/test/ui/consts/control-flow/exhaustive-c-like-enum-match.rs
index 6bbbdd972a26c..7887fd12e5764 100644
--- a/src/test/ui/consts/control-flow/exhaustive-c-like-enum-match.rs
+++ b/src/test/ui/consts/control-flow/exhaustive-c-like-enum-match.rs
@@ -3,6 +3,7 @@
 // check-pass
 
 #![feature(const_if_match)]
+#![feature(const_fn)]
 
 enum E {
     A,
diff --git a/src/test/ui/consts/control-flow/feature-gate-const-if-match.if_match.stderr b/src/test/ui/consts/control-flow/feature-gate-const-if-match.if_match.stderr
index 21e3f2af15ad6..95096723b3c95 100644
--- a/src/test/ui/consts/control-flow/feature-gate-const-if-match.if_match.stderr
+++ b/src/test/ui/consts/control-flow/feature-gate-const-if-match.if_match.stderr
@@ -1,5 +1,5 @@
 error: fatal error triggered by #[rustc_error]
-  --> $DIR/feature-gate-const-if-match.rs:108:1
+  --> $DIR/feature-gate-const-if-match.rs:109:1
    |
 LL | / fn main() {
 LL | |     let _ = [0; {
diff --git a/src/test/ui/consts/control-flow/feature-gate-const-if-match.rs b/src/test/ui/consts/control-flow/feature-gate-const-if-match.rs
index 00576d50ac66b..e4b65257531fd 100644
--- a/src/test/ui/consts/control-flow/feature-gate-const-if-match.rs
+++ b/src/test/ui/consts/control-flow/feature-gate-const-if-match.rs
@@ -6,6 +6,7 @@
 
 #![feature(rustc_attrs)]
 #![cfg_attr(if_match, feature(const_if_match))]
+#![feature(const_fn)]
 
 const _: i32 = if true { //[stock]~ ERROR `if` is not allowed in a `const`
     5
diff --git a/src/test/ui/consts/control-flow/feature-gate-const-if-match.stock.stderr b/src/test/ui/consts/control-flow/feature-gate-const-if-match.stock.stderr
index d3c6a51923ffb..e846ee4ab6a41 100644
--- a/src/test/ui/consts/control-flow/feature-gate-const-if-match.stock.stderr
+++ b/src/test/ui/consts/control-flow/feature-gate-const-if-match.stock.stderr
@@ -1,5 +1,5 @@
 error[E0658]: `if` is not allowed in a `const`
-  --> $DIR/feature-gate-const-if-match.rs:10:16
+  --> $DIR/feature-gate-const-if-match.rs:11:16
    |
 LL |   const _: i32 = if true {
    |  ________________^
@@ -13,7 +13,7 @@ LL | | };
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable
 
 error[E0658]: `if` is not allowed in a `const`
-  --> $DIR/feature-gate-const-if-match.rs:16:16
+  --> $DIR/feature-gate-const-if-match.rs:17:16
    |
 LL |   const _: i32 = if let Some(true) = Some(false) {
    |  ________________^
@@ -27,7 +27,7 @@ LL | | };
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable
 
 error[E0658]: `match` is not allowed in a `const`
-  --> $DIR/feature-gate-const-if-match.rs:22:16
+  --> $DIR/feature-gate-const-if-match.rs:23:16
    |
 LL |   const _: i32 = match 1 {
    |  ________________^
@@ -41,7 +41,7 @@ LL | | };
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable
 
 error[E0658]: `if` is not allowed in a `static`
-  --> $DIR/feature-gate-const-if-match.rs:29:13
+  --> $DIR/feature-gate-const-if-match.rs:30:13
    |
 LL |     let x = if true { 0 } else { 1 };
    |             ^^^^^^^^^^^^^^^^^^^^^^^^
@@ -50,7 +50,7 @@ LL |     let x = if true { 0 } else { 1 };
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable
 
 error[E0658]: `match` is not allowed in a `static`
-  --> $DIR/feature-gate-const-if-match.rs:31:13
+  --> $DIR/feature-gate-const-if-match.rs:32:13
    |
 LL |     let x = match x { 0 => 1, _ => 0 };
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -59,7 +59,7 @@ LL |     let x = match x { 0 => 1, _ => 0 };
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable
 
 error[E0658]: `if` is not allowed in a `static`
-  --> $DIR/feature-gate-const-if-match.rs:33:5
+  --> $DIR/feature-gate-const-if-match.rs:34:5
    |
 LL |     if let Some(x) = Some(x) { x } else { 1 }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -68,7 +68,7 @@ LL |     if let Some(x) = Some(x) { x } else { 1 }
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable
 
 error[E0658]: `if` is not allowed in a `static mut`
-  --> $DIR/feature-gate-const-if-match.rs:38:13
+  --> $DIR/feature-gate-const-if-match.rs:39:13
    |
 LL |     let x = if true { 0 } else { 1 };
    |             ^^^^^^^^^^^^^^^^^^^^^^^^
@@ -77,7 +77,7 @@ LL |     let x = if true { 0 } else { 1 };
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable
 
 error[E0658]: `match` is not allowed in a `static mut`
-  --> $DIR/feature-gate-const-if-match.rs:40:13
+  --> $DIR/feature-gate-const-if-match.rs:41:13
    |
 LL |     let x = match x { 0 => 1, _ => 0 };
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -86,7 +86,7 @@ LL |     let x = match x { 0 => 1, _ => 0 };
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable
 
 error[E0658]: `if` is not allowed in a `static mut`
-  --> $DIR/feature-gate-const-if-match.rs:42:5
+  --> $DIR/feature-gate-const-if-match.rs:43:5
    |
 LL |     if let Some(x) = Some(x) { x } else { 1 }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -95,7 +95,7 @@ LL |     if let Some(x) = Some(x) { x } else { 1 }
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable
 
 error[E0658]: `if` is not allowed in a `const fn`
-  --> $DIR/feature-gate-const-if-match.rs:47:5
+  --> $DIR/feature-gate-const-if-match.rs:48:5
    |
 LL |     if true { 5 } else { 6 }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^
@@ -104,7 +104,7 @@ LL |     if true { 5 } else { 6 }
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable
 
 error[E0658]: `if` is not allowed in a `const fn`
-  --> $DIR/feature-gate-const-if-match.rs:51:5
+  --> $DIR/feature-gate-const-if-match.rs:52:5
    |
 LL | /     if let Some(true) = a {
 LL | |         0
@@ -117,7 +117,7 @@ LL | |     }
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable
 
 error[E0658]: `match` is not allowed in a `const fn`
-  --> $DIR/feature-gate-const-if-match.rs:59:5
+  --> $DIR/feature-gate-const-if-match.rs:60:5
    |
 LL | /     match i {
 LL | |         i if i > 10 => i,
@@ -130,7 +130,7 @@ LL | |     }
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable
 
 error[E0658]: `if` is not allowed in a `const fn`
-  --> $DIR/feature-gate-const-if-match.rs:90:17
+  --> $DIR/feature-gate-const-if-match.rs:91:17
    |
 LL |         let x = if y { 0 } else { 1 };
    |                 ^^^^^^^^^^^^^^^^^^^^^
@@ -139,7 +139,7 @@ LL |         let x = if y { 0 } else { 1 };
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable
 
 error[E0658]: `match` is not allowed in a `const fn`
-  --> $DIR/feature-gate-const-if-match.rs:92:17
+  --> $DIR/feature-gate-const-if-match.rs:93:17
    |
 LL |         let x = match x { 0 => 1, _ => 0 };
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -148,7 +148,7 @@ LL |         let x = match x { 0 => 1, _ => 0 };
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable
 
 error[E0658]: `if` is not allowed in a `const fn`
-  --> $DIR/feature-gate-const-if-match.rs:94:9
+  --> $DIR/feature-gate-const-if-match.rs:95:9
    |
 LL |         if let Some(x) = Some(x) { x } else { 1 }
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -157,7 +157,7 @@ LL |         if let Some(x) = Some(x) { x } else { 1 }
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable
 
 error[E0658]: `if` is not allowed in a `const`
-  --> $DIR/feature-gate-const-if-match.rs:110:17
+  --> $DIR/feature-gate-const-if-match.rs:111:17
    |
 LL |         let x = if false { 0 } else { 1 };
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -166,7 +166,7 @@ LL |         let x = if false { 0 } else { 1 };
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable
 
 error[E0658]: `match` is not allowed in a `const`
-  --> $DIR/feature-gate-const-if-match.rs:112:17
+  --> $DIR/feature-gate-const-if-match.rs:113:17
    |
 LL |         let x = match x { 0 => 1, _ => 0 };
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -175,7 +175,7 @@ LL |         let x = match x { 0 => 1, _ => 0 };
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable
 
 error[E0658]: `if` is not allowed in a `const`
-  --> $DIR/feature-gate-const-if-match.rs:114:9
+  --> $DIR/feature-gate-const-if-match.rs:115:9
    |
 LL |         if let Some(x) = Some(x) { x } else { 1 }
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -184,7 +184,7 @@ LL |         if let Some(x) = Some(x) { x } else { 1 }
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable
 
 error[E0658]: `if` is not allowed in a `const`
-  --> $DIR/feature-gate-const-if-match.rs:67:21
+  --> $DIR/feature-gate-const-if-match.rs:68:21
    |
 LL |     const IF: i32 = if true { 5 } else { 6 };
    |                     ^^^^^^^^^^^^^^^^^^^^^^^^
@@ -193,7 +193,7 @@ LL |     const IF: i32 = if true { 5 } else { 6 };
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable
 
 error[E0658]: `if` is not allowed in a `const`
-  --> $DIR/feature-gate-const-if-match.rs:70:25
+  --> $DIR/feature-gate-const-if-match.rs:71:25
    |
 LL |     const IF_LET: i32 = if let Some(true) = None { 5 } else { 6 };
    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -202,7 +202,7 @@ LL |     const IF_LET: i32 = if let Some(true) = None { 5 } else { 6 };
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable
 
 error[E0658]: `match` is not allowed in a `const`
-  --> $DIR/feature-gate-const-if-match.rs:73:24
+  --> $DIR/feature-gate-const-if-match.rs:74:24
    |
 LL |     const MATCH: i32 = match 0 { 1 => 2, _ => 0 };
    |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -211,7 +211,7 @@ LL |     const MATCH: i32 = match 0 { 1 => 2, _ => 0 };
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable
 
 error[E0658]: `if` is not allowed in a `const`
-  --> $DIR/feature-gate-const-if-match.rs:78:21
+  --> $DIR/feature-gate-const-if-match.rs:79:21
    |
 LL |     const IF: i32 = if true { 5 } else { 6 };
    |                     ^^^^^^^^^^^^^^^^^^^^^^^^
@@ -220,7 +220,7 @@ LL |     const IF: i32 = if true { 5 } else { 6 };
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable
 
 error[E0658]: `if` is not allowed in a `const`
-  --> $DIR/feature-gate-const-if-match.rs:81:25
+  --> $DIR/feature-gate-const-if-match.rs:82:25
    |
 LL |     const IF_LET: i32 = if let Some(true) = None { 5 } else { 6 };
    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -229,7 +229,7 @@ LL |     const IF_LET: i32 = if let Some(true) = None { 5 } else { 6 };
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable
 
 error[E0658]: `match` is not allowed in a `const`
-  --> $DIR/feature-gate-const-if-match.rs:84:24
+  --> $DIR/feature-gate-const-if-match.rs:85:24
    |
 LL |     const MATCH: i32 = match 0 { 1 => 2, _ => 0 };
    |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -238,7 +238,7 @@ LL |     const MATCH: i32 = match 0 { 1 => 2, _ => 0 };
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable
 
 error[E0019]: constant contains unimplemented expression type
-  --> $DIR/feature-gate-const-if-match.rs:114:21
+  --> $DIR/feature-gate-const-if-match.rs:115:21
    |
 LL |         if let Some(x) = Some(x) { x } else { 1 }
    |                     ^
diff --git a/src/test/ui/consts/control-flow/short-circuit-let.rs b/src/test/ui/consts/control-flow/short-circuit-let.rs
index 8cee2a54f56d3..4b20a2124c356 100644
--- a/src/test/ui/consts/control-flow/short-circuit-let.rs
+++ b/src/test/ui/consts/control-flow/short-circuit-let.rs
@@ -4,6 +4,7 @@
 
 #![feature(const_if_match)]
 #![feature(const_panic)]
+#![feature(const_fn)]
 
 const X: i32 = {
     let mut x = 0;
diff --git a/src/test/ui/consts/control-flow/single_variant_match_ice.rs b/src/test/ui/consts/control-flow/single_variant_match_ice.rs
index 823605ff034f1..bb0fce66c4d89 100644
--- a/src/test/ui/consts/control-flow/single_variant_match_ice.rs
+++ b/src/test/ui/consts/control-flow/single_variant_match_ice.rs
@@ -1,6 +1,6 @@
 // check-pass
 
-#![feature(const_if_match)]
+#![feature(const_if_match, const_fn)]
 
 enum Foo {
     Prob,
diff --git a/src/test/ui/consts/validate_never_arrays.rs b/src/test/ui/consts/validate_never_arrays.rs
index 1270dc4ee30e6..9610b7b22f161 100644
--- a/src/test/ui/consts/validate_never_arrays.rs
+++ b/src/test/ui/consts/validate_never_arrays.rs
@@ -1,4 +1,4 @@
-#![feature(const_raw_ptr_deref)]
+#![feature(const_raw_ptr_deref, never_type)]
 
 const FOO: &[!; 1] = unsafe { &*(1_usize as *const [!; 1]) }; //~ ERROR undefined behavior
 
diff --git a/src/test/ui/empty/empty-never-array.rs b/src/test/ui/empty/empty-never-array.rs
index 38702f8d28f90..f0ecea42f39c8 100644
--- a/src/test/ui/empty/empty-never-array.rs
+++ b/src/test/ui/empty/empty-never-array.rs
@@ -1,3 +1,5 @@
+#![feature(never_type)]
+
 enum Helper<T, U> {
     T(T, [!; 0]),
     #[allow(dead_code)]
diff --git a/src/test/ui/empty/empty-never-array.stderr b/src/test/ui/empty/empty-never-array.stderr
index defcd256f7d98..d865b59f0b945 100644
--- a/src/test/ui/empty/empty-never-array.stderr
+++ b/src/test/ui/empty/empty-never-array.stderr
@@ -1,5 +1,5 @@
 error[E0005]: refutable pattern in local binding: `T(_, _)` not covered
-  --> $DIR/empty-never-array.rs:8:9
+  --> $DIR/empty-never-array.rs:10:9
    |
 LL | / enum Helper<T, U> {
 LL | |     T(T, [!; 0]),
@@ -20,7 +20,7 @@ LL |     if let Helper::U(u) = Helper::T(t, []) { /* */ }
    |
 
 error[E0381]: use of possibly-uninitialized variable: `u`
-  --> $DIR/empty-never-array.rs:10:5
+  --> $DIR/empty-never-array.rs:12:5
    |
 LL |     u
    |     ^ use of possibly-uninitialized `u`
diff --git a/src/test/ui/feature-gates/feature-gate-exhaustive-patterns.rs b/src/test/ui/feature-gates/feature-gate-exhaustive-patterns.rs
index c27089d2a0590..f0cc9ea70550e 100644
--- a/src/test/ui/feature-gates/feature-gate-exhaustive-patterns.rs
+++ b/src/test/ui/feature-gates/feature-gate-exhaustive-patterns.rs
@@ -1,3 +1,5 @@
+#![feature(never_type)]
+
 fn foo() -> Result<u32, !> {
     Ok(123)
 }
diff --git a/src/test/ui/feature-gates/feature-gate-exhaustive-patterns.stderr b/src/test/ui/feature-gates/feature-gate-exhaustive-patterns.stderr
index e599a9ee150f4..08c36cece4cf9 100644
--- a/src/test/ui/feature-gates/feature-gate-exhaustive-patterns.stderr
+++ b/src/test/ui/feature-gates/feature-gate-exhaustive-patterns.stderr
@@ -1,5 +1,5 @@
 error[E0005]: refutable pattern in local binding: `Err(_)` not covered
-  --> $DIR/feature-gate-exhaustive-patterns.rs:6:9
+  --> $DIR/feature-gate-exhaustive-patterns.rs:8:9
    |
 LL |     let Ok(_x) = foo();
    |         ^^^^^^ pattern `Err(_)` not covered
diff --git a/src/test/ui/feature-gates/feature-gate-never_type.rs b/src/test/ui/feature-gates/feature-gate-never_type.rs
new file mode 100644
index 0000000000000..be8c27dbb1b02
--- /dev/null
+++ b/src/test/ui/feature-gates/feature-gate-never_type.rs
@@ -0,0 +1,17 @@
+// Test that ! errors when used in illegal positions with feature(never_type) disabled
+
+trait Foo {
+    type Wub;
+}
+
+type Ma = (u32, !, i32); //~ ERROR type is experimental
+type Meeshka = Vec<!>; //~ ERROR type is experimental
+type Mow = &'static fn(!) -> !; //~ ERROR type is experimental
+type Skwoz = &'static mut !; //~ ERROR type is experimental
+
+impl Foo for Meeshka {
+    type Wub = !; //~ ERROR type is experimental
+}
+
+fn main() {
+}
diff --git a/src/test/ui/feature-gates/feature-gate-never_type.stderr b/src/test/ui/feature-gates/feature-gate-never_type.stderr
new file mode 100644
index 0000000000000..d86ab99b82bd5
--- /dev/null
+++ b/src/test/ui/feature-gates/feature-gate-never_type.stderr
@@ -0,0 +1,48 @@
+error[E0658]: The `!` type is experimental
+  --> $DIR/feature-gate-never_type.rs:7:17
+   |
+LL | type Ma = (u32, !, i32);
+   |                 ^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/35121
+   = help: add `#![feature(never_type)]` to the crate attributes to enable
+
+error[E0658]: The `!` type is experimental
+  --> $DIR/feature-gate-never_type.rs:8:20
+   |
+LL | type Meeshka = Vec<!>;
+   |                    ^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/35121
+   = help: add `#![feature(never_type)]` to the crate attributes to enable
+
+error[E0658]: The `!` type is experimental
+  --> $DIR/feature-gate-never_type.rs:9:24
+   |
+LL | type Mow = &'static fn(!) -> !;
+   |                        ^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/35121
+   = help: add `#![feature(never_type)]` to the crate attributes to enable
+
+error[E0658]: The `!` type is experimental
+  --> $DIR/feature-gate-never_type.rs:10:27
+   |
+LL | type Skwoz = &'static mut !;
+   |                           ^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/35121
+   = help: add `#![feature(never_type)]` to the crate attributes to enable
+
+error[E0658]: The `!` type is experimental
+  --> $DIR/feature-gate-never_type.rs:13:16
+   |
+LL |     type Wub = !;
+   |                ^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/35121
+   = help: add `#![feature(never_type)]` to the crate attributes to enable
+
+error: aborting due to 5 previous errors
+
+For more information about this error, try `rustc --explain E0658`.
diff --git a/src/test/ui/for-loop-while/loop-break-value.rs b/src/test/ui/for-loop-while/loop-break-value.rs
index 29848bb0cedaa..d7209fc4de867 100644
--- a/src/test/ui/for-loop-while/loop-break-value.rs
+++ b/src/test/ui/for-loop-while/loop-break-value.rs
@@ -1,6 +1,7 @@
 // run-pass
 
 #![allow(unreachable_code)]
+#![feature(never_type)]
 
 #[allow(unused)]
 fn never_returns() {
diff --git a/src/test/ui/lint/must_use-unit.rs b/src/test/ui/lint/must_use-unit.rs
index 8f59bab26d3ef..4dd4798abb7ce 100644
--- a/src/test/ui/lint/must_use-unit.rs
+++ b/src/test/ui/lint/must_use-unit.rs
@@ -1,3 +1,4 @@
+#![feature(never_type)]
 #![deny(unused_must_use)]
 
 #[must_use]
diff --git a/src/test/ui/lint/must_use-unit.stderr b/src/test/ui/lint/must_use-unit.stderr
index a6d0259a081af..0a9939b2015b7 100644
--- a/src/test/ui/lint/must_use-unit.stderr
+++ b/src/test/ui/lint/must_use-unit.stderr
@@ -1,17 +1,17 @@
 error: unused return value of `foo` that must be used
-  --> $DIR/must_use-unit.rs:12:5
+  --> $DIR/must_use-unit.rs:13:5
    |
 LL |     foo();
    |     ^^^^^^
    |
 note: lint level defined here
-  --> $DIR/must_use-unit.rs:1:9
+  --> $DIR/must_use-unit.rs:2:9
    |
 LL | #![deny(unused_must_use)]
    |         ^^^^^^^^^^^^^^^
 
 error: unused return value of `bar` that must be used
-  --> $DIR/must_use-unit.rs:14:5
+  --> $DIR/must_use-unit.rs:15:5
    |
 LL |     bar();
    |     ^^^^^^
diff --git a/src/test/ui/lint/uninitialized-zeroed.rs b/src/test/ui/lint/uninitialized-zeroed.rs
index ed2369fd650b0..473be434a7524 100644
--- a/src/test/ui/lint/uninitialized-zeroed.rs
+++ b/src/test/ui/lint/uninitialized-zeroed.rs
@@ -2,7 +2,7 @@
 // This test checks that calling `mem::{uninitialized,zeroed}` with certain types results
 // in a lint.
 
-#![feature(rustc_attrs)]
+#![feature(never_type, rustc_attrs)]
 #![allow(deprecated)]
 #![deny(invalid_value)]
 
diff --git a/src/test/ui/loops/loop-break-value.rs b/src/test/ui/loops/loop-break-value.rs
index c4fb68c02784e..6c4160c36aa39 100644
--- a/src/test/ui/loops/loop-break-value.rs
+++ b/src/test/ui/loops/loop-break-value.rs
@@ -1,3 +1,5 @@
+#![feature(never_type)]
+
 fn main() {
     let val: ! = loop { break break; };
     //~^ ERROR mismatched types
diff --git a/src/test/ui/loops/loop-break-value.stderr b/src/test/ui/loops/loop-break-value.stderr
index 1f2d81ff03f0a..3bb0cd50d63fb 100644
--- a/src/test/ui/loops/loop-break-value.stderr
+++ b/src/test/ui/loops/loop-break-value.stderr
@@ -1,5 +1,5 @@
 warning: denote infinite loops with `loop { ... }`
-  --> $DIR/loop-break-value.rs:24:5
+  --> $DIR/loop-break-value.rs:26:5
    |
 LL |     'while_loop: while true {
    |     ^^^^^^^^^^^^^^^^^^^^^^^ help: use `loop`
@@ -7,7 +7,7 @@ LL |     'while_loop: while true {
    = note: `#[warn(while_true)]` on by default
 
 error[E0571]: `break` with value from a `while` loop
-  --> $DIR/loop-break-value.rs:26:9
+  --> $DIR/loop-break-value.rs:28:9
    |
 LL |         break ();
    |         ^^^^^^^^ can only break with a value inside `loop` or breakable block
@@ -18,7 +18,7 @@ LL |         break;
    |         ^^^^^
 
 error[E0571]: `break` with value from a `while` loop
-  --> $DIR/loop-break-value.rs:28:13
+  --> $DIR/loop-break-value.rs:30:13
    |
 LL |             break 'while_loop 123;
    |             ^^^^^^^^^^^^^^^^^^^^^ can only break with a value inside `loop` or breakable block
@@ -29,7 +29,7 @@ LL |             break;
    |             ^^^^^
 
 error[E0571]: `break` with value from a `while` loop
-  --> $DIR/loop-break-value.rs:36:12
+  --> $DIR/loop-break-value.rs:38:12
    |
 LL |         if break () {
    |            ^^^^^^^^ can only break with a value inside `loop` or breakable block
@@ -40,7 +40,7 @@ LL |         if break {
    |            ^^^^^
 
 error[E0571]: `break` with value from a `while` loop
-  --> $DIR/loop-break-value.rs:41:9
+  --> $DIR/loop-break-value.rs:43:9
    |
 LL |         break None;
    |         ^^^^^^^^^^ can only break with a value inside `loop` or breakable block
@@ -51,7 +51,7 @@ LL |         break;
    |         ^^^^^
 
 error[E0571]: `break` with value from a `while` loop
-  --> $DIR/loop-break-value.rs:47:13
+  --> $DIR/loop-break-value.rs:49:13
    |
 LL |             break 'while_let_loop "nope";
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ can only break with a value inside `loop` or breakable block
@@ -62,7 +62,7 @@ LL |             break;
    |             ^^^^^
 
 error[E0571]: `break` with value from a `for` loop
-  --> $DIR/loop-break-value.rs:54:9
+  --> $DIR/loop-break-value.rs:56:9
    |
 LL |         break ();
    |         ^^^^^^^^ can only break with a value inside `loop` or breakable block
@@ -73,7 +73,7 @@ LL |         break;
    |         ^^^^^
 
 error[E0571]: `break` with value from a `for` loop
-  --> $DIR/loop-break-value.rs:55:9
+  --> $DIR/loop-break-value.rs:57:9
    |
 LL |         break [()];
    |         ^^^^^^^^^^ can only break with a value inside `loop` or breakable block
@@ -84,7 +84,7 @@ LL |         break;
    |         ^^^^^
 
 error[E0571]: `break` with value from a `for` loop
-  --> $DIR/loop-break-value.rs:62:13
+  --> $DIR/loop-break-value.rs:64:13
    |
 LL |             break 'for_loop Some(17);
    |             ^^^^^^^^^^^^^^^^^^^^^^^^ can only break with a value inside `loop` or breakable block
@@ -95,7 +95,7 @@ LL |             break;
    |             ^^^^^
 
 error[E0308]: mismatched types
-  --> $DIR/loop-break-value.rs:2:31
+  --> $DIR/loop-break-value.rs:4:31
    |
 LL |     let val: ! = loop { break break; };
    |                               ^^^^^ expected `!`, found `()`
@@ -104,31 +104,31 @@ LL |     let val: ! = loop { break break; };
            found unit type `()`
 
 error[E0308]: mismatched types
-  --> $DIR/loop-break-value.rs:9:19
+  --> $DIR/loop-break-value.rs:11:19
    |
 LL |             break 123;
    |                   ^^^ expected `&str`, found integer
 
 error[E0308]: mismatched types
-  --> $DIR/loop-break-value.rs:14:15
+  --> $DIR/loop-break-value.rs:16:15
    |
 LL |         break "asdf";
    |               ^^^^^^ expected `i32`, found `&str`
 
 error[E0308]: mismatched types
-  --> $DIR/loop-break-value.rs:19:31
+  --> $DIR/loop-break-value.rs:21:31
    |
 LL |             break 'outer_loop "nope";
    |                               ^^^^^^ expected `i32`, found `&str`
 
 error[E0308]: mismatched types
-  --> $DIR/loop-break-value.rs:71:26
+  --> $DIR/loop-break-value.rs:73:26
    |
 LL |                 break 'c 123;
    |                          ^^^ expected `()`, found integer
 
 error[E0308]: mismatched types
-  --> $DIR/loop-break-value.rs:78:15
+  --> $DIR/loop-break-value.rs:80:15
    |
 LL |         break (break, break);
    |               ^^^^^^^^^^^^^^ expected `()`, found tuple
@@ -137,13 +137,13 @@ LL |         break (break, break);
                   found tuple `(!, !)`
 
 error[E0308]: mismatched types
-  --> $DIR/loop-break-value.rs:83:15
+  --> $DIR/loop-break-value.rs:85:15
    |
 LL |         break 2;
    |               ^ expected `()`, found integer
 
 error[E0308]: mismatched types
-  --> $DIR/loop-break-value.rs:88:9
+  --> $DIR/loop-break-value.rs:90:9
    |
 LL |         break;
    |         ^^^^^
diff --git a/src/test/ui/mir/mir_calls_to_shims.rs b/src/test/ui/mir/mir_calls_to_shims.rs
index df7c45ad1d1c7..6f13d5612ce51 100644
--- a/src/test/ui/mir/mir_calls_to_shims.rs
+++ b/src/test/ui/mir/mir_calls_to_shims.rs
@@ -2,6 +2,7 @@
 // ignore-wasm32-bare compiled with panic=abort by default
 
 #![feature(fn_traits)]
+#![feature(never_type)]
 
 use std::panic;
 
diff --git a/src/test/ui/never_type/adjust_never.rs b/src/test/ui/never_type/adjust_never.rs
index e4d15c8a17dfa..0d7d2c0ed3fa9 100644
--- a/src/test/ui/never_type/adjust_never.rs
+++ b/src/test/ui/never_type/adjust_never.rs
@@ -2,6 +2,8 @@
 
 // check-pass
 
+#![feature(never_type)]
+
 fn main() {
     let x: ! = panic!();
     let y: u32 = x;
diff --git a/src/test/ui/never_type/auto-traits.rs b/src/test/ui/never_type/auto-traits.rs
index 8a02720ab27fd..2d9689888cb30 100644
--- a/src/test/ui/never_type/auto-traits.rs
+++ b/src/test/ui/never_type/auto-traits.rs
@@ -1,6 +1,7 @@
 // check-pass
 
 #![feature(optin_builtin_traits)]
+#![feature(never_type)]
 
 fn main() {
     enum Void {}
diff --git a/src/test/ui/never_type/call-fn-never-arg-wrong-type.rs b/src/test/ui/never_type/call-fn-never-arg-wrong-type.rs
index a2b44e91f1141..d06637e74a2f2 100644
--- a/src/test/ui/never_type/call-fn-never-arg-wrong-type.rs
+++ b/src/test/ui/never_type/call-fn-never-arg-wrong-type.rs
@@ -1,5 +1,7 @@
 // Test that we can't pass other types for !
 
+#![feature(never_type)]
+
 fn foo(x: !) -> ! {
     x
 }
diff --git a/src/test/ui/never_type/call-fn-never-arg-wrong-type.stderr b/src/test/ui/never_type/call-fn-never-arg-wrong-type.stderr
index 69049fc8db69b..eacef1dc3302d 100644
--- a/src/test/ui/never_type/call-fn-never-arg-wrong-type.stderr
+++ b/src/test/ui/never_type/call-fn-never-arg-wrong-type.stderr
@@ -1,5 +1,5 @@
 error[E0308]: mismatched types
-  --> $DIR/call-fn-never-arg-wrong-type.rs:8:9
+  --> $DIR/call-fn-never-arg-wrong-type.rs:10:9
    |
 LL |     foo("wow");
    |         ^^^^^ expected `!`, found `&str`
diff --git a/src/test/ui/never_type/call-fn-never-arg.rs b/src/test/ui/never_type/call-fn-never-arg.rs
index 55a7b79157a82..9d355817ee80d 100644
--- a/src/test/ui/never_type/call-fn-never-arg.rs
+++ b/src/test/ui/never_type/call-fn-never-arg.rs
@@ -2,6 +2,7 @@
 
 // check-pass
 
+#![feature(never_type)]
 #![allow(unreachable_code)]
 
 fn foo(x: !) -> ! {
diff --git a/src/test/ui/never_type/cast-never.rs b/src/test/ui/never_type/cast-never.rs
index fbba114ab3274..0139ebe4640be 100644
--- a/src/test/ui/never_type/cast-never.rs
+++ b/src/test/ui/never_type/cast-never.rs
@@ -2,6 +2,8 @@
 
 // check-pass
 
+#![feature(never_type)]
+
 fn main() {
     let x: ! = panic!();
     let y: u32 = x as u32;
diff --git a/src/test/ui/never_type/defaulted-never-note.rs b/src/test/ui/never_type/defaulted-never-note.rs
index c58b611748423..1780cb6535d05 100644
--- a/src/test/ui/never_type/defaulted-never-note.rs
+++ b/src/test/ui/never_type/defaulted-never-note.rs
@@ -1,6 +1,6 @@
 // We need to opt into the `never_type_fallback` feature
 // to trigger the requirement that this is testing.
-#![feature(never_type_fallback)]
+#![feature(never_type, never_type_fallback)]
 
 #![allow(unused)]
 
diff --git a/src/test/ui/never_type/dispatch_from_dyn_zst.rs b/src/test/ui/never_type/dispatch_from_dyn_zst.rs
index 342d5e4791515..764f58ce9e805 100644
--- a/src/test/ui/never_type/dispatch_from_dyn_zst.rs
+++ b/src/test/ui/never_type/dispatch_from_dyn_zst.rs
@@ -1,6 +1,6 @@
 // run-pass
 
-#![feature(unsize, dispatch_from_dyn)]
+#![feature(unsize, dispatch_from_dyn, never_type)]
 
 #![allow(dead_code)]
 
diff --git a/src/test/ui/never_type/diverging-fallback-control-flow.rs b/src/test/ui/never_type/diverging-fallback-control-flow.rs
index df04437b1ae20..ea4881049d792 100644
--- a/src/test/ui/never_type/diverging-fallback-control-flow.rs
+++ b/src/test/ui/never_type/diverging-fallback-control-flow.rs
@@ -11,7 +11,7 @@
 // These represent current behavior, but are pretty dubious.  I would
 // like to revisit these and potentially change them. --nmatsakis
 
-#![feature(never_type_fallback)]
+#![feature(never_type, never_type_fallback)]
 
 trait BadDefault {
     fn default() -> Self;
diff --git a/src/test/ui/never_type/impl-for-never.rs b/src/test/ui/never_type/impl-for-never.rs
index cbfda9a2cc00a..9423f08858b9b 100644
--- a/src/test/ui/never_type/impl-for-never.rs
+++ b/src/test/ui/never_type/impl-for-never.rs
@@ -1,5 +1,7 @@
 // run-pass
 
+#![feature(never_type)]
+
 // Test that we can call static methods on ! both directly and when it appears in a generic
 
 trait StringifyType {
diff --git a/src/test/ui/never_type/issue-44402.rs b/src/test/ui/never_type/issue-44402.rs
index 0e6588bbe78ea..699e480dfe7e5 100644
--- a/src/test/ui/never_type/issue-44402.rs
+++ b/src/test/ui/never_type/issue-44402.rs
@@ -1,6 +1,7 @@
 // check-pass
 
 #![allow(dead_code)]
+#![feature(never_type)]
 #![feature(exhaustive_patterns)]
 
 // Regression test for inhabitedness check. The old
diff --git a/src/test/ui/never_type/never-assign-dead-code.rs b/src/test/ui/never_type/never-assign-dead-code.rs
index 5c1300c715128..7bb7c87097c50 100644
--- a/src/test/ui/never_type/never-assign-dead-code.rs
+++ b/src/test/ui/never_type/never-assign-dead-code.rs
@@ -2,6 +2,7 @@
 
 // check-pass
 
+#![feature(never_type)]
 #![warn(unused)]
 
 fn main() {
diff --git a/src/test/ui/never_type/never-assign-dead-code.stderr b/src/test/ui/never_type/never-assign-dead-code.stderr
index 1dc15251d1aa1..1860150fa8bc6 100644
--- a/src/test/ui/never_type/never-assign-dead-code.stderr
+++ b/src/test/ui/never_type/never-assign-dead-code.stderr
@@ -1,5 +1,5 @@
 warning: unreachable statement
-  --> $DIR/never-assign-dead-code.rs:9:5
+  --> $DIR/never-assign-dead-code.rs:10:5
    |
 LL |     let x: ! = panic!("aah");
    |                ------------- any code following this expression is unreachable
@@ -7,7 +7,7 @@ LL |     drop(x);
    |     ^^^^^^^^ unreachable statement
    |
 note: lint level defined here
-  --> $DIR/never-assign-dead-code.rs:5:9
+  --> $DIR/never-assign-dead-code.rs:6:9
    |
 LL | #![warn(unused)]
    |         ^^^^^^
@@ -15,7 +15,7 @@ LL | #![warn(unused)]
    = note: this warning originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
 
 warning: unreachable call
-  --> $DIR/never-assign-dead-code.rs:9:5
+  --> $DIR/never-assign-dead-code.rs:10:5
    |
 LL |     drop(x);
    |     ^^^^ - any code following this expression is unreachable
@@ -23,13 +23,13 @@ LL |     drop(x);
    |     unreachable call
 
 warning: unused variable: `x`
-  --> $DIR/never-assign-dead-code.rs:8:9
+  --> $DIR/never-assign-dead-code.rs:9:9
    |
 LL |     let x: ! = panic!("aah");
    |         ^ help: consider prefixing with an underscore: `_x`
    |
 note: lint level defined here
-  --> $DIR/never-assign-dead-code.rs:5:9
+  --> $DIR/never-assign-dead-code.rs:6:9
    |
 LL | #![warn(unused)]
    |         ^^^^^^
diff --git a/src/test/ui/never_type/never-assign-wrong-type.rs b/src/test/ui/never_type/never-assign-wrong-type.rs
index 9ca1ac7462d4d..67e26f5663f41 100644
--- a/src/test/ui/never_type/never-assign-wrong-type.rs
+++ b/src/test/ui/never_type/never-assign-wrong-type.rs
@@ -1,5 +1,6 @@
 // Test that we can't use another type in place of !
 
+#![feature(never_type)]
 #![deny(warnings)]
 
 fn main() {
diff --git a/src/test/ui/never_type/never-assign-wrong-type.stderr b/src/test/ui/never_type/never-assign-wrong-type.stderr
index 4349d98029eaf..ce34d9483247f 100644
--- a/src/test/ui/never_type/never-assign-wrong-type.stderr
+++ b/src/test/ui/never_type/never-assign-wrong-type.stderr
@@ -1,5 +1,5 @@
 error[E0308]: mismatched types
-  --> $DIR/never-assign-wrong-type.rs:6:16
+  --> $DIR/never-assign-wrong-type.rs:7:16
    |
 LL |     let x: ! = "hello";
    |            -   ^^^^^^^ expected `!`, found `&str`
diff --git a/src/test/ui/never_type/never-associated-type.rs b/src/test/ui/never_type/never-associated-type.rs
index 45e54b9bf7c18..3bb917c931635 100644
--- a/src/test/ui/never_type/never-associated-type.rs
+++ b/src/test/ui/never_type/never-associated-type.rs
@@ -2,6 +2,8 @@
 
 // check-pass
 
+#![feature(never_type)]
+
 trait Foo {
     type Wow;
 
diff --git a/src/test/ui/never_type/never-from-impl-is-reserved.rs b/src/test/ui/never_type/never-from-impl-is-reserved.rs
index df74b6a53f888..9d16015bdc129 100644
--- a/src/test/ui/never_type/never-from-impl-is-reserved.rs
+++ b/src/test/ui/never_type/never-from-impl-is-reserved.rs
@@ -1,5 +1,7 @@
 // check that the `for<T> T: From<!>` impl is reserved
 
+#![feature(never_type)]
+
 pub struct MyFoo;
 pub trait MyTrait {}
 
diff --git a/src/test/ui/never_type/never-from-impl-is-reserved.stderr b/src/test/ui/never_type/never-from-impl-is-reserved.stderr
index 8b3155988ea95..8b8d0f4ea73be 100644
--- a/src/test/ui/never_type/never-from-impl-is-reserved.stderr
+++ b/src/test/ui/never_type/never-from-impl-is-reserved.stderr
@@ -1,5 +1,5 @@
 error[E0119]: conflicting implementations of trait `MyTrait` for type `MyFoo`:
-  --> $DIR/never-from-impl-is-reserved.rs:8:1
+  --> $DIR/never-from-impl-is-reserved.rs:10:1
    |
 LL | impl MyTrait for MyFoo {}
    | ---------------------- first implementation here
diff --git a/src/test/ui/never_type/never-result.rs b/src/test/ui/never_type/never-result.rs
index 800553fce874d..35af37910ef3e 100644
--- a/src/test/ui/never_type/never-result.rs
+++ b/src/test/ui/never_type/never-result.rs
@@ -5,6 +5,8 @@
 
 // Test that we can extract a ! through pattern matching then use it as several different types.
 
+#![feature(never_type)]
+
 fn main() {
     let x: Result<u32, !> = Ok(123);
     match x {
diff --git a/src/test/ui/never_type/never-type-arg.rs b/src/test/ui/never_type/never-type-arg.rs
index 3cbb114f43b94..13cd59e6aa9f1 100644
--- a/src/test/ui/never_type/never-type-arg.rs
+++ b/src/test/ui/never_type/never-type-arg.rs
@@ -2,6 +2,8 @@
 
 // check-pass
 
+#![feature(never_type)]
+
 struct Wub;
 
 impl PartialEq<!> for Wub {
diff --git a/src/test/ui/never_type/never-type-rvalues.rs b/src/test/ui/never_type/never-type-rvalues.rs
index 9bfc5572b9ee6..9ccc73dbf92d4 100644
--- a/src/test/ui/never_type/never-type-rvalues.rs
+++ b/src/test/ui/never_type/never-type-rvalues.rs
@@ -1,5 +1,6 @@
 // run-pass
 
+#![feature(never_type)]
 #![allow(dead_code)]
 #![allow(path_statements)]
 #![allow(unreachable_patterns)]
diff --git a/src/test/ui/never_type/never-value-fallback-issue-66757.rs b/src/test/ui/never_type/never-value-fallback-issue-66757.rs
new file mode 100644
index 0000000000000..f2e9e087307db
--- /dev/null
+++ b/src/test/ui/never_type/never-value-fallback-issue-66757.rs
@@ -0,0 +1,29 @@
+// Regression test for #66757
+//
+// Test than when you have a `!` value (e.g., the local variable
+// never) and an uninferred variable (here the argument to `From`) it
+// doesn't fallback to `()` but rather `!`.
+//
+// run-pass
+
+#![feature(never_type)]
+
+// FIXME(#67225) -- this should be true even without the fallback gate.
+#![feature(never_type_fallback)]
+
+struct E;
+
+impl From<!> for E {
+    fn from(_: !) -> E {
+        E
+    }
+}
+
+#[allow(unreachable_code)]
+#[allow(dead_code)]
+fn foo(never: !) {
+    <E as From<!>>::from(never);  // Ok
+    <E as From<_>>::from(never);  // Inference fails here
+}
+
+fn main() { }
diff --git a/src/test/ui/never_type/never_transmute_never.rs b/src/test/ui/never_type/never_transmute_never.rs
index cdf04de19e523..fce3ced9aac7f 100644
--- a/src/test/ui/never_type/never_transmute_never.rs
+++ b/src/test/ui/never_type/never_transmute_never.rs
@@ -2,6 +2,7 @@
 
 #![crate_type="lib"]
 
+#![feature(never_type)]
 #![allow(dead_code)]
 #![allow(unreachable_code)]
 #![allow(unused_variables)]
diff --git a/src/test/ui/never_type/panic-uninitialized-zeroed.rs b/src/test/ui/never_type/panic-uninitialized-zeroed.rs
index e5e0e188de63c..e0c30160b9e94 100644
--- a/src/test/ui/never_type/panic-uninitialized-zeroed.rs
+++ b/src/test/ui/never_type/panic-uninitialized-zeroed.rs
@@ -3,6 +3,7 @@
 // This test checks that instantiating an uninhabited type via `mem::{uninitialized,zeroed}` results
 // in a runtime panic.
 
+#![feature(never_type)]
 #![allow(deprecated, invalid_value)]
 
 use std::{mem, panic};
diff --git a/src/test/ui/never_type/try_from.rs b/src/test/ui/never_type/try_from.rs
index 977ea3656b3dd..50451576f9c97 100644
--- a/src/test/ui/never_type/try_from.rs
+++ b/src/test/ui/never_type/try_from.rs
@@ -5,6 +5,8 @@
 // This test was added to show the motivation for doing this
 // over `TryFrom` being blanket impl for all `T: From`
 
+#![feature(never_type)]
+
 use std::convert::{TryInto, Infallible};
 
 struct Foo<T> {
diff --git a/src/test/ui/pattern/usefulness/match-privately-empty.rs b/src/test/ui/pattern/usefulness/match-privately-empty.rs
index ea608651387b7..315eb03d16564 100644
--- a/src/test/ui/pattern/usefulness/match-privately-empty.rs
+++ b/src/test/ui/pattern/usefulness/match-privately-empty.rs
@@ -1,3 +1,4 @@
+#![feature(never_type)]
 #![feature(exhaustive_patterns)]
 
 mod private {
diff --git a/src/test/ui/pattern/usefulness/match-privately-empty.stderr b/src/test/ui/pattern/usefulness/match-privately-empty.stderr
index 66d0d9587741b..f79d180a1b8b5 100644
--- a/src/test/ui/pattern/usefulness/match-privately-empty.stderr
+++ b/src/test/ui/pattern/usefulness/match-privately-empty.stderr
@@ -1,5 +1,5 @@
 error[E0004]: non-exhaustive patterns: `Some(Private { misc: true, .. })` not covered
-  --> $DIR/match-privately-empty.rs:12:11
+  --> $DIR/match-privately-empty.rs:13:11
    |
 LL |     match private::DATA {
    |           ^^^^^^^^^^^^^ pattern `Some(Private { misc: true, .. })` not covered
diff --git a/src/test/ui/print_type_sizes/uninhabited.rs b/src/test/ui/print_type_sizes/uninhabited.rs
index 3a2ca19d8e0c3..ae4e492456af9 100644
--- a/src/test/ui/print_type_sizes/uninhabited.rs
+++ b/src/test/ui/print_type_sizes/uninhabited.rs
@@ -4,6 +4,7 @@
 // ^-- needed because `--pass check` does not emit the output needed.
 //     FIXME: consider using an attribute instead of side-effects.
 
+#![feature(never_type)]
 #![feature(start)]
 
 #[start]
diff --git a/src/test/ui/reachable/expr_add.rs b/src/test/ui/reachable/expr_add.rs
index 640c2a2cf8fcc..b45e5daf42c8d 100644
--- a/src/test/ui/reachable/expr_add.rs
+++ b/src/test/ui/reachable/expr_add.rs
@@ -1,3 +1,4 @@
+#![feature(never_type)]
 #![allow(unused_variables)]
 #![deny(unreachable_code)]
 
diff --git a/src/test/ui/reachable/expr_add.stderr b/src/test/ui/reachable/expr_add.stderr
index 11c41fdc3946b..880dea1cc3516 100644
--- a/src/test/ui/reachable/expr_add.stderr
+++ b/src/test/ui/reachable/expr_add.stderr
@@ -1,5 +1,5 @@
 error: unreachable expression
-  --> $DIR/expr_add.rs:16:13
+  --> $DIR/expr_add.rs:17:13
    |
 LL |     let x = Foo + return;
    |             ^^^^^^------
@@ -8,7 +8,7 @@ LL |     let x = Foo + return;
    |             unreachable expression
    |
 note: lint level defined here
-  --> $DIR/expr_add.rs:2:9
+  --> $DIR/expr_add.rs:3:9
    |
 LL | #![deny(unreachable_code)]
    |         ^^^^^^^^^^^^^^^^
diff --git a/src/test/ui/reachable/expr_assign.rs b/src/test/ui/reachable/expr_assign.rs
index 3914fb32432ef..e547f75e2697b 100644
--- a/src/test/ui/reachable/expr_assign.rs
+++ b/src/test/ui/reachable/expr_assign.rs
@@ -1,3 +1,4 @@
+#![feature(never_type)]
 #![allow(unused_variables)]
 #![allow(unused_assignments)]
 #![allow(dead_code)]
diff --git a/src/test/ui/reachable/expr_assign.stderr b/src/test/ui/reachable/expr_assign.stderr
index 90aec15e3be1e..3004da0406328 100644
--- a/src/test/ui/reachable/expr_assign.stderr
+++ b/src/test/ui/reachable/expr_assign.stderr
@@ -1,5 +1,5 @@
 error: unreachable expression
-  --> $DIR/expr_assign.rs:9:5
+  --> $DIR/expr_assign.rs:10:5
    |
 LL |     x = return;
    |     ^^^^------
@@ -8,13 +8,13 @@ LL |     x = return;
    |     unreachable expression
    |
 note: lint level defined here
-  --> $DIR/expr_assign.rs:4:9
+  --> $DIR/expr_assign.rs:5:9
    |
 LL | #![deny(unreachable_code)]
    |         ^^^^^^^^^^^^^^^^
 
 error: unreachable expression
-  --> $DIR/expr_assign.rs:19:14
+  --> $DIR/expr_assign.rs:20:14
    |
 LL |         *p = return;
    |         --   ^^^^^^ unreachable expression
@@ -22,7 +22,7 @@ LL |         *p = return;
    |         any code following this expression is unreachable
 
 error: unreachable expression
-  --> $DIR/expr_assign.rs:25:15
+  --> $DIR/expr_assign.rs:26:15
    |
 LL |     *{return; &mut i} = 22;
    |       ------  ^^^^^^ unreachable expression
diff --git a/src/test/ui/reachable/expr_call.rs b/src/test/ui/reachable/expr_call.rs
index ce1a94e3c4a25..1eaa96c3ce773 100644
--- a/src/test/ui/reachable/expr_call.rs
+++ b/src/test/ui/reachable/expr_call.rs
@@ -1,3 +1,4 @@
+#![feature(never_type)]
 #![allow(unused_variables)]
 #![allow(unused_assignments)]
 #![allow(dead_code)]
diff --git a/src/test/ui/reachable/expr_call.stderr b/src/test/ui/reachable/expr_call.stderr
index 613fc31b8613e..ae8b4dd87b5b9 100644
--- a/src/test/ui/reachable/expr_call.stderr
+++ b/src/test/ui/reachable/expr_call.stderr
@@ -1,5 +1,5 @@
 error: unreachable expression
-  --> $DIR/expr_call.rs:12:17
+  --> $DIR/expr_call.rs:13:17
    |
 LL |     foo(return, 22);
    |         ------  ^^ unreachable expression
@@ -7,13 +7,13 @@ LL |     foo(return, 22);
    |         any code following this expression is unreachable
    |
 note: lint level defined here
-  --> $DIR/expr_call.rs:4:9
+  --> $DIR/expr_call.rs:5:9
    |
 LL | #![deny(unreachable_code)]
    |         ^^^^^^^^^^^^^^^^
 
 error: unreachable call
-  --> $DIR/expr_call.rs:17:5
+  --> $DIR/expr_call.rs:18:5
    |
 LL |     bar(return);
    |     ^^^ ------ any code following this expression is unreachable
diff --git a/src/test/ui/reachable/expr_cast.rs b/src/test/ui/reachable/expr_cast.rs
index 76a7306b9d9e0..f53bcb97e6972 100644
--- a/src/test/ui/reachable/expr_cast.rs
+++ b/src/test/ui/reachable/expr_cast.rs
@@ -2,7 +2,7 @@
 #![allow(unused_assignments)]
 #![allow(dead_code)]
 #![deny(unreachable_code)]
-#![feature(type_ascription)]
+#![feature(never_type, type_ascription)]
 
 fn a() {
     // the cast is unreachable:
diff --git a/src/test/ui/reachable/expr_method.rs b/src/test/ui/reachable/expr_method.rs
index e74a7daec8828..d917df05b3c3d 100644
--- a/src/test/ui/reachable/expr_method.rs
+++ b/src/test/ui/reachable/expr_method.rs
@@ -1,3 +1,4 @@
+#![feature(never_type)]
 #![allow(unused_variables)]
 #![allow(unused_assignments)]
 #![allow(dead_code)]
diff --git a/src/test/ui/reachable/expr_method.stderr b/src/test/ui/reachable/expr_method.stderr
index 7475cf7a365b5..82a0745f0629f 100644
--- a/src/test/ui/reachable/expr_method.stderr
+++ b/src/test/ui/reachable/expr_method.stderr
@@ -1,5 +1,5 @@
 error: unreachable expression
-  --> $DIR/expr_method.rs:15:21
+  --> $DIR/expr_method.rs:16:21
    |
 LL |     Foo.foo(return, 22);
    |             ------  ^^ unreachable expression
@@ -7,13 +7,13 @@ LL |     Foo.foo(return, 22);
    |             any code following this expression is unreachable
    |
 note: lint level defined here
-  --> $DIR/expr_method.rs:4:9
+  --> $DIR/expr_method.rs:5:9
    |
 LL | #![deny(unreachable_code)]
    |         ^^^^^^^^^^^^^^^^
 
 error: unreachable call
-  --> $DIR/expr_method.rs:20:9
+  --> $DIR/expr_method.rs:21:9
    |
 LL |     Foo.bar(return);
    |         ^^^ ------ any code following this expression is unreachable
diff --git a/src/test/ui/reachable/expr_type.rs b/src/test/ui/reachable/expr_type.rs
index ff647bda0e87e..8d32397b54248 100644
--- a/src/test/ui/reachable/expr_type.rs
+++ b/src/test/ui/reachable/expr_type.rs
@@ -2,7 +2,7 @@
 #![allow(unused_assignments)]
 #![allow(dead_code)]
 #![deny(unreachable_code)]
-#![feature(type_ascription)]
+#![feature(never_type, type_ascription)]
 
 fn a() {
     // the cast is unreachable:
diff --git a/src/test/ui/reachable/expr_unary.rs b/src/test/ui/reachable/expr_unary.rs
index 6f221c360cb17..e229d22ebc798 100644
--- a/src/test/ui/reachable/expr_unary.rs
+++ b/src/test/ui/reachable/expr_unary.rs
@@ -1,3 +1,4 @@
+#![feature(never_type)]
 #![allow(unused_variables)]
 #![allow(unused_assignments)]
 #![allow(dead_code)]
diff --git a/src/test/ui/reachable/expr_unary.stderr b/src/test/ui/reachable/expr_unary.stderr
index a576f92092335..f5c3564217bba 100644
--- a/src/test/ui/reachable/expr_unary.stderr
+++ b/src/test/ui/reachable/expr_unary.stderr
@@ -1,11 +1,11 @@
 error[E0600]: cannot apply unary operator `!` to type `!`
-  --> $DIR/expr_unary.rs:7:16
+  --> $DIR/expr_unary.rs:8:16
    |
 LL |     let x: ! = ! { return; };
    |                ^^^^^^^^^^^^^ cannot apply unary operator `!`
 
 error: unreachable expression
-  --> $DIR/expr_unary.rs:7:16
+  --> $DIR/expr_unary.rs:8:16
    |
 LL |     let x: ! = ! { return; };
    |                ^^^^------^^^
@@ -14,7 +14,7 @@ LL |     let x: ! = ! { return; };
    |                unreachable expression
    |
 note: lint level defined here
-  --> $DIR/expr_unary.rs:4:9
+  --> $DIR/expr_unary.rs:5:9
    |
 LL | #![deny(unreachable_code)]
    |         ^^^^^^^^^^^^^^^^
diff --git a/src/test/ui/reachable/unreachable-loop-patterns.rs b/src/test/ui/reachable/unreachable-loop-patterns.rs
index c8ff56539116f..4de29c3c3d761 100644
--- a/src/test/ui/reachable/unreachable-loop-patterns.rs
+++ b/src/test/ui/reachable/unreachable-loop-patterns.rs
@@ -1,4 +1,4 @@
-#![feature(never_type_fallback)]
+#![feature(never_type, never_type_fallback)]
 #![feature(exhaustive_patterns)]
 
 #![allow(unreachable_code)]
diff --git a/src/test/ui/reachable/unreachable-try-pattern.rs b/src/test/ui/reachable/unreachable-try-pattern.rs
index e2d89e93a2aa0..23360e73f4a3a 100644
--- a/src/test/ui/reachable/unreachable-try-pattern.rs
+++ b/src/test/ui/reachable/unreachable-try-pattern.rs
@@ -1,5 +1,5 @@
 // check-pass
-#![feature(exhaustive_patterns)]
+#![feature(never_type, exhaustive_patterns)]
 #![warn(unreachable_code)]
 #![warn(unreachable_patterns)]
 
diff --git a/src/test/ui/reachable/unwarned-match-on-never.rs b/src/test/ui/reachable/unwarned-match-on-never.rs
index c38ea6ab9ad01..71f8fe3a783e2 100644
--- a/src/test/ui/reachable/unwarned-match-on-never.rs
+++ b/src/test/ui/reachable/unwarned-match-on-never.rs
@@ -1,6 +1,8 @@
 #![deny(unreachable_code)]
 #![allow(dead_code)]
 
+#![feature(never_type)]
+
 fn foo(x: !) -> bool {
     // Explicit matches on the never type are unwarned.
     match x {}
diff --git a/src/test/ui/reachable/unwarned-match-on-never.stderr b/src/test/ui/reachable/unwarned-match-on-never.stderr
index 6710fcb777f7a..6b2fb4a33c1e8 100644
--- a/src/test/ui/reachable/unwarned-match-on-never.stderr
+++ b/src/test/ui/reachable/unwarned-match-on-never.stderr
@@ -1,5 +1,5 @@
 error: unreachable expression
-  --> $DIR/unwarned-match-on-never.rs:8:5
+  --> $DIR/unwarned-match-on-never.rs:10:5
    |
 LL |     match x {}
    |           - any code following this expression is unreachable
@@ -14,7 +14,7 @@ LL | #![deny(unreachable_code)]
    |         ^^^^^^^^^^^^^^^^
 
 error: unreachable arm
-  --> $DIR/unwarned-match-on-never.rs:13:15
+  --> $DIR/unwarned-match-on-never.rs:15:15
    |
 LL |     match (return) {
    |           -------- any code following this expression is unreachable
@@ -22,7 +22,7 @@ LL |         () => ()
    |               ^^ unreachable arm
 
 error: unreachable expression
-  --> $DIR/unwarned-match-on-never.rs:19:5
+  --> $DIR/unwarned-match-on-never.rs:21:5
    |
 LL |       return;
    |       ------ any code following this expression is unreachable
diff --git a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/auxiliary/uninhabited.rs b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/auxiliary/uninhabited.rs
index e074183a0490c..a2735d4cbfb29 100644
--- a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/auxiliary/uninhabited.rs
+++ b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/auxiliary/uninhabited.rs
@@ -1,4 +1,5 @@
 #![crate_type = "rlib"]
+#![feature(never_type)]
 
 #[non_exhaustive]
 pub enum UninhabitedEnum {
diff --git a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/coercions.rs b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/coercions.rs
index 5684ee6b7bf86..80b9dc4c1c338 100644
--- a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/coercions.rs
+++ b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/coercions.rs
@@ -1,4 +1,5 @@
 // aux-build:uninhabited.rs
+#![feature(never_type)]
 
 extern crate uninhabited;
 
diff --git a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/coercions.stderr b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/coercions.stderr
index d50e5f6b795f7..d2d319f50c78d 100644
--- a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/coercions.stderr
+++ b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/coercions.stderr
@@ -1,5 +1,5 @@
 error[E0308]: mismatched types
-  --> $DIR/coercions.rs:22:5
+  --> $DIR/coercions.rs:23:5
    |
 LL | fn cannot_coerce_empty_enum_to_anything(x: UninhabitedEnum) -> A {
    |                                                                - expected `A` because of return type
@@ -7,7 +7,7 @@ LL |     x
    |     ^ expected struct `A`, found enum `uninhabited::UninhabitedEnum`
 
 error[E0308]: mismatched types
-  --> $DIR/coercions.rs:26:5
+  --> $DIR/coercions.rs:27:5
    |
 LL | fn cannot_coerce_empty_tuple_struct_to_anything(x: UninhabitedTupleStruct) -> A {
    |                                                                               - expected `A` because of return type
@@ -15,7 +15,7 @@ LL |     x
    |     ^ expected struct `A`, found struct `uninhabited::UninhabitedTupleStruct`
 
 error[E0308]: mismatched types
-  --> $DIR/coercions.rs:30:5
+  --> $DIR/coercions.rs:31:5
    |
 LL | fn cannot_coerce_empty_struct_to_anything(x: UninhabitedStruct) -> A {
    |                                                                    - expected `A` because of return type
@@ -23,7 +23,7 @@ LL |     x
    |     ^ expected struct `A`, found struct `uninhabited::UninhabitedStruct`
 
 error[E0308]: mismatched types
-  --> $DIR/coercions.rs:34:5
+  --> $DIR/coercions.rs:35:5
    |
 LL | fn cannot_coerce_enum_with_empty_variants_to_anything(x: UninhabitedVariants) -> A {
    |                                                                                  - expected `A` because of return type
diff --git a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/coercions_same_crate.rs b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/coercions_same_crate.rs
index c3c0ce650d73e..6b911dd989cc5 100644
--- a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/coercions_same_crate.rs
+++ b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/coercions_same_crate.rs
@@ -1,3 +1,5 @@
+#![feature(never_type)]
+
 #[non_exhaustive]
 pub enum UninhabitedEnum {
 }
diff --git a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/coercions_same_crate.stderr b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/coercions_same_crate.stderr
index 16a62a992497d..fd2c56974bd4a 100644
--- a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/coercions_same_crate.stderr
+++ b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/coercions_same_crate.stderr
@@ -1,5 +1,5 @@
 error[E0308]: mismatched types
-  --> $DIR/coercions_same_crate.rs:28:5
+  --> $DIR/coercions_same_crate.rs:30:5
    |
 LL | fn cannot_coerce_empty_enum_to_anything(x: UninhabitedEnum) -> A {
    |                                                                - expected `A` because of return type
@@ -7,7 +7,7 @@ LL |     x
    |     ^ expected struct `A`, found enum `UninhabitedEnum`
 
 error[E0308]: mismatched types
-  --> $DIR/coercions_same_crate.rs:32:5
+  --> $DIR/coercions_same_crate.rs:34:5
    |
 LL | fn cannot_coerce_empty_tuple_struct_to_anything(x: UninhabitedTupleStruct) -> A {
    |                                                                               - expected `A` because of return type
@@ -15,7 +15,7 @@ LL |     x
    |     ^ expected struct `A`, found struct `UninhabitedTupleStruct`
 
 error[E0308]: mismatched types
-  --> $DIR/coercions_same_crate.rs:36:5
+  --> $DIR/coercions_same_crate.rs:38:5
    |
 LL | fn cannot_coerce_empty_struct_to_anything(x: UninhabitedStruct) -> A {
    |                                                                    - expected `A` because of return type
@@ -23,7 +23,7 @@ LL |     x
    |     ^ expected struct `A`, found struct `UninhabitedStruct`
 
 error[E0308]: mismatched types
-  --> $DIR/coercions_same_crate.rs:40:5
+  --> $DIR/coercions_same_crate.rs:42:5
    |
 LL | fn cannot_coerce_enum_with_empty_variants_to_anything(x: UninhabitedVariants) -> A {
    |                                                                                  - expected `A` because of return type
diff --git a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match.rs b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match.rs
index 511b6b1bf8f6c..98a7fdbc5049a 100644
--- a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match.rs
+++ b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match.rs
@@ -1,4 +1,5 @@
 // aux-build:uninhabited.rs
+#![feature(never_type)]
 
 extern crate uninhabited;
 
diff --git a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match.stderr b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match.stderr
index b903e9b288ef7..af82022e1da99 100644
--- a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match.stderr
+++ b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match.stderr
@@ -1,5 +1,5 @@
 error[E0004]: non-exhaustive patterns: pattern `IndirectUninhabitedEnum` of type `uninhabited::IndirectUninhabitedEnum` is not handled
-  --> $DIR/indirect_match.rs:18:11
+  --> $DIR/indirect_match.rs:19:11
    |
 LL |     match x {}
    |           ^
@@ -7,7 +7,7 @@ LL |     match x {}
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: pattern `IndirectUninhabitedStruct` of type `uninhabited::IndirectUninhabitedStruct` is not handled
-  --> $DIR/indirect_match.rs:22:11
+  --> $DIR/indirect_match.rs:23:11
    |
 LL |     match x {}
    |           ^
@@ -15,7 +15,7 @@ LL |     match x {}
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: pattern `IndirectUninhabitedTupleStruct` of type `uninhabited::IndirectUninhabitedTupleStruct` is not handled
-  --> $DIR/indirect_match.rs:26:11
+  --> $DIR/indirect_match.rs:27:11
    |
 LL |     match x {}
    |           ^
@@ -23,7 +23,7 @@ LL |     match x {}
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: pattern `IndirectUninhabitedVariants` of type `uninhabited::IndirectUninhabitedVariants` is not handled
-  --> $DIR/indirect_match.rs:32:11
+  --> $DIR/indirect_match.rs:33:11
    |
 LL |     match x {}
    |           ^
diff --git a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match_same_crate.rs b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match_same_crate.rs
index 9c3ec4240a5fd..8f090fe886a00 100644
--- a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match_same_crate.rs
+++ b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match_same_crate.rs
@@ -1,3 +1,5 @@
+#![feature(never_type)]
+
 #[non_exhaustive]
 pub enum UninhabitedEnum {
 }
diff --git a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match_same_crate.stderr b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match_same_crate.stderr
index f94616dc64b1b..c03018a523647 100644
--- a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match_same_crate.stderr
+++ b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match_same_crate.stderr
@@ -1,5 +1,5 @@
 error[E0004]: non-exhaustive patterns: pattern `IndirectUninhabitedEnum` of type `IndirectUninhabitedEnum` is not handled
-  --> $DIR/indirect_match_same_crate.rs:32:11
+  --> $DIR/indirect_match_same_crate.rs:34:11
    |
 LL | pub struct IndirectUninhabitedEnum(UninhabitedEnum);
    | ----------------------------------------------------
@@ -13,7 +13,7 @@ LL |     match x {}
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: pattern `IndirectUninhabitedStruct` of type `IndirectUninhabitedStruct` is not handled
-  --> $DIR/indirect_match_same_crate.rs:36:11
+  --> $DIR/indirect_match_same_crate.rs:38:11
    |
 LL | pub struct IndirectUninhabitedStruct(UninhabitedStruct);
    | --------------------------------------------------------
@@ -27,7 +27,7 @@ LL |     match x {}
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: pattern `IndirectUninhabitedTupleStruct` of type `IndirectUninhabitedTupleStruct` is not handled
-  --> $DIR/indirect_match_same_crate.rs:40:11
+  --> $DIR/indirect_match_same_crate.rs:42:11
    |
 LL | pub struct IndirectUninhabitedTupleStruct(UninhabitedTupleStruct);
    | ------------------------------------------------------------------
@@ -41,7 +41,7 @@ LL |     match x {}
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: pattern `IndirectUninhabitedVariants` of type `IndirectUninhabitedVariants` is not handled
-  --> $DIR/indirect_match_same_crate.rs:46:11
+  --> $DIR/indirect_match_same_crate.rs:48:11
    |
 LL | pub struct IndirectUninhabitedVariants(UninhabitedVariants);
    | ------------------------------------------------------------
diff --git a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match_with_exhaustive_patterns.rs b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match_with_exhaustive_patterns.rs
index 68ac42ef5878d..be86519ecb159 100644
--- a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match_with_exhaustive_patterns.rs
+++ b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match_with_exhaustive_patterns.rs
@@ -1,6 +1,7 @@
 // aux-build:uninhabited.rs
 #![deny(unreachable_patterns)]
 #![feature(exhaustive_patterns)]
+#![feature(never_type)]
 
 extern crate uninhabited;
 
diff --git a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match_with_exhaustive_patterns.stderr b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match_with_exhaustive_patterns.stderr
index 2c2e542934177..17a8d01007205 100644
--- a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match_with_exhaustive_patterns.stderr
+++ b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match_with_exhaustive_patterns.stderr
@@ -1,5 +1,5 @@
 error[E0004]: non-exhaustive patterns: type `uninhabited::IndirectUninhabitedEnum` is non-empty
-  --> $DIR/indirect_match_with_exhaustive_patterns.rs:22:11
+  --> $DIR/indirect_match_with_exhaustive_patterns.rs:23:11
    |
 LL |     match x {}
    |           ^
@@ -7,7 +7,7 @@ LL |     match x {}
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: type `uninhabited::IndirectUninhabitedStruct` is non-empty
-  --> $DIR/indirect_match_with_exhaustive_patterns.rs:26:11
+  --> $DIR/indirect_match_with_exhaustive_patterns.rs:27:11
    |
 LL |     match x {}
    |           ^
@@ -15,7 +15,7 @@ LL |     match x {}
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: type `uninhabited::IndirectUninhabitedTupleStruct` is non-empty
-  --> $DIR/indirect_match_with_exhaustive_patterns.rs:30:11
+  --> $DIR/indirect_match_with_exhaustive_patterns.rs:31:11
    |
 LL |     match x {}
    |           ^
@@ -23,7 +23,7 @@ LL |     match x {}
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: type `uninhabited::IndirectUninhabitedVariants` is non-empty
-  --> $DIR/indirect_match_with_exhaustive_patterns.rs:36:11
+  --> $DIR/indirect_match_with_exhaustive_patterns.rs:37:11
    |
 LL |     match x {}
    |           ^
diff --git a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match_with_exhaustive_patterns_same_crate.rs b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match_with_exhaustive_patterns_same_crate.rs
index 06c318414f03f..60289aa780378 100644
--- a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match_with_exhaustive_patterns_same_crate.rs
+++ b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/indirect_match_with_exhaustive_patterns_same_crate.rs
@@ -2,6 +2,7 @@
 
 #![deny(unreachable_patterns)]
 #![feature(exhaustive_patterns)]
+#![feature(never_type)]
 
 #[non_exhaustive]
 pub enum UninhabitedEnum {
diff --git a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match.rs b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match.rs
index fd3dbca04c00f..e54098d4d48b9 100644
--- a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match.rs
+++ b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match.rs
@@ -1,4 +1,5 @@
 // aux-build:uninhabited.rs
+#![feature(never_type)]
 
 extern crate uninhabited;
 
diff --git a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match.stderr b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match.stderr
index de3fa900cd622..de39688f45a4d 100644
--- a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match.stderr
+++ b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match.stderr
@@ -1,5 +1,5 @@
 error[E0004]: non-exhaustive patterns: type `uninhabited::UninhabitedEnum` is non-empty
-  --> $DIR/match.rs:18:11
+  --> $DIR/match.rs:19:11
    |
 LL |     match x {}
    |           ^
@@ -7,7 +7,7 @@ LL |     match x {}
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: pattern `UninhabitedStruct` of type `uninhabited::UninhabitedStruct` is not handled
-  --> $DIR/match.rs:22:11
+  --> $DIR/match.rs:23:11
    |
 LL |     match x {}
    |           ^
@@ -15,7 +15,7 @@ LL |     match x {}
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: pattern `UninhabitedTupleStruct` of type `uninhabited::UninhabitedTupleStruct` is not handled
-  --> $DIR/match.rs:26:11
+  --> $DIR/match.rs:27:11
    |
 LL |     match x {}
    |           ^
@@ -23,7 +23,7 @@ LL |     match x {}
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: multiple patterns of type `uninhabited::UninhabitedVariants` are not handled
-  --> $DIR/match.rs:30:11
+  --> $DIR/match.rs:31:11
    |
 LL |     match x {}
    |           ^
diff --git a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_same_crate.rs b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_same_crate.rs
index c31688add91b2..ebbdfba15f3a3 100644
--- a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_same_crate.rs
+++ b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_same_crate.rs
@@ -1,3 +1,5 @@
+#![feature(never_type)]
+
 #[non_exhaustive]
 pub enum UninhabitedEnum {
 }
diff --git a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_same_crate.stderr b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_same_crate.stderr
index 3dd1a914d5542..c39df05a8f74e 100644
--- a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_same_crate.stderr
+++ b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_same_crate.stderr
@@ -1,5 +1,5 @@
 error[E0004]: non-exhaustive patterns: pattern `UninhabitedStruct` of type `UninhabitedStruct` is not handled
-  --> $DIR/match_same_crate.rs:28:11
+  --> $DIR/match_same_crate.rs:30:11
    |
 LL |   pub struct UninhabitedStruct {
    |   -          ----------------- variant not covered
@@ -15,7 +15,7 @@ LL |       match x {}
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: pattern `UninhabitedTupleStruct` of type `UninhabitedTupleStruct` is not handled
-  --> $DIR/match_same_crate.rs:32:11
+  --> $DIR/match_same_crate.rs:34:11
    |
 LL | pub struct UninhabitedTupleStruct(!);
    | -------------------------------------
@@ -29,7 +29,7 @@ LL |     match x {}
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: multiple patterns of type `UninhabitedVariants` are not handled
-  --> $DIR/match_same_crate.rs:36:11
+  --> $DIR/match_same_crate.rs:38:11
    |
 LL | / pub enum UninhabitedVariants {
 LL | |     #[non_exhaustive] Tuple(!),
diff --git a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_with_exhaustive_patterns.rs b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_with_exhaustive_patterns.rs
index 37d739834d20c..900dfff652ea6 100644
--- a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_with_exhaustive_patterns.rs
+++ b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_with_exhaustive_patterns.rs
@@ -1,6 +1,7 @@
 // aux-build:uninhabited.rs
 #![deny(unreachable_patterns)]
 #![feature(exhaustive_patterns)]
+#![feature(never_type)]
 
 extern crate uninhabited;
 
diff --git a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_with_exhaustive_patterns.stderr b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_with_exhaustive_patterns.stderr
index 3b56c6890710d..48a888bc50be0 100644
--- a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_with_exhaustive_patterns.stderr
+++ b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_with_exhaustive_patterns.stderr
@@ -1,5 +1,5 @@
 error[E0004]: non-exhaustive patterns: type `uninhabited::UninhabitedEnum` is non-empty
-  --> $DIR/match_with_exhaustive_patterns.rs:21:11
+  --> $DIR/match_with_exhaustive_patterns.rs:22:11
    |
 LL |     match x {}
    |           ^
@@ -7,7 +7,7 @@ LL |     match x {}
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: type `uninhabited::UninhabitedStruct` is non-empty
-  --> $DIR/match_with_exhaustive_patterns.rs:25:11
+  --> $DIR/match_with_exhaustive_patterns.rs:26:11
    |
 LL |     match x {}
    |           ^
@@ -15,7 +15,7 @@ LL |     match x {}
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: type `uninhabited::UninhabitedTupleStruct` is non-empty
-  --> $DIR/match_with_exhaustive_patterns.rs:29:11
+  --> $DIR/match_with_exhaustive_patterns.rs:30:11
    |
 LL |     match x {}
    |           ^
@@ -23,7 +23,7 @@ LL |     match x {}
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: type `uninhabited::UninhabitedVariants` is non-empty
-  --> $DIR/match_with_exhaustive_patterns.rs:33:11
+  --> $DIR/match_with_exhaustive_patterns.rs:34:11
    |
 LL |     match x {}
    |           ^
diff --git a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_with_exhaustive_patterns_same_crate.rs b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_with_exhaustive_patterns_same_crate.rs
index 2b2e4b6e77d87..de5530485f3e6 100644
--- a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_with_exhaustive_patterns_same_crate.rs
+++ b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_with_exhaustive_patterns_same_crate.rs
@@ -2,6 +2,7 @@
 
 #![deny(unreachable_patterns)]
 #![feature(exhaustive_patterns)]
+#![feature(never_type)]
 
 #[non_exhaustive]
 pub enum UninhabitedEnum {
diff --git a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/patterns_same_crate.rs b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/patterns_same_crate.rs
index 3d4cca4505ef1..ffc496a975ecf 100644
--- a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/patterns_same_crate.rs
+++ b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/patterns_same_crate.rs
@@ -1,5 +1,6 @@
 #![deny(unreachable_patterns)]
 #![feature(exhaustive_patterns)]
+#![feature(never_type)]
 
 #[non_exhaustive]
 pub enum UninhabitedEnum {
diff --git a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/patterns_same_crate.stderr b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/patterns_same_crate.stderr
index fea883f891200..e3de94be1282e 100644
--- a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/patterns_same_crate.stderr
+++ b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/patterns_same_crate.stderr
@@ -1,5 +1,5 @@
 error: unreachable pattern
-  --> $DIR/patterns_same_crate.rs:51:9
+  --> $DIR/patterns_same_crate.rs:52:9
    |
 LL |         Some(_x) => (),
    |         ^^^^^^^^
@@ -11,25 +11,25 @@ LL | #![deny(unreachable_patterns)]
    |         ^^^^^^^^^^^^^^^^^^^^
 
 error: unreachable pattern
-  --> $DIR/patterns_same_crate.rs:56:9
+  --> $DIR/patterns_same_crate.rs:57:9
    |
 LL |         Some(_x) => (),
    |         ^^^^^^^^
 
 error: unreachable pattern
-  --> $DIR/patterns_same_crate.rs:60:15
+  --> $DIR/patterns_same_crate.rs:61:15
    |
 LL |     while let PartiallyInhabitedVariants::Struct { x } = partially_inhabited_variant() {
    |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: unreachable pattern
-  --> $DIR/patterns_same_crate.rs:64:15
+  --> $DIR/patterns_same_crate.rs:65:15
    |
 LL |     while let Some(_x) = uninhabited_struct() {
    |               ^^^^^^^^
 
 error: unreachable pattern
-  --> $DIR/patterns_same_crate.rs:67:15
+  --> $DIR/patterns_same_crate.rs:68:15
    |
 LL |     while let Some(_x) = uninhabited_tuple_struct() {
    |               ^^^^^^^^
diff --git a/src/test/ui/suggestions/option-content-move2.rs b/src/test/ui/suggestions/option-content-move2.rs
new file mode 100644
index 0000000000000..88e8a5b7aeef0
--- /dev/null
+++ b/src/test/ui/suggestions/option-content-move2.rs
@@ -0,0 +1,16 @@
+struct NotCopyable;
+
+fn func<F: FnMut() -> H, H: FnMut()>(_: F) {}
+
+fn parse() {
+    let mut var = None;
+    func(|| {
+        // Shouldn't suggest `move ||.as_ref()` here
+        move || {
+        //~^ ERROR: cannot move out of `var`
+            var = Some(NotCopyable);
+        }
+    });
+}
+
+fn main() {}
diff --git a/src/test/ui/suggestions/option-content-move2.stderr b/src/test/ui/suggestions/option-content-move2.stderr
new file mode 100644
index 0000000000000..71f745374e5ac
--- /dev/null
+++ b/src/test/ui/suggestions/option-content-move2.stderr
@@ -0,0 +1,18 @@
+error[E0507]: cannot move out of `var`, a captured variable in an `FnMut` closure
+  --> $DIR/option-content-move2.rs:9:9
+   |
+LL |     let mut var = None;
+   |         ------- captured outer variable
+...
+LL |         move || {
+   |         ^^^^^^^ move out of `var` occurs here
+LL |
+LL |             var = Some(NotCopyable);
+   |             ---
+   |             |
+   |             move occurs because `var` has type `std::option::Option<NotCopyable>`, which does not implement the `Copy` trait
+   |             move occurs due to use in closure
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0507`.
diff --git a/src/test/ui/traits/reservation-impls/reservation-impl-non-lattice-ok.rs b/src/test/ui/traits/reservation-impls/reservation-impl-non-lattice-ok.rs
index 0e0197803b761..f14589ccf846d 100644
--- a/src/test/ui/traits/reservation-impls/reservation-impl-non-lattice-ok.rs
+++ b/src/test/ui/traits/reservation-impls/reservation-impl-non-lattice-ok.rs
@@ -30,7 +30,7 @@
 //
 // [ii]: http://smallcultfollowing.com/babysteps/blog/2016/09/24/intersection-impls/
 
-#![feature(rustc_attrs)]
+#![feature(rustc_attrs, never_type)]
 
 trait MyTrait {}
 
diff --git a/src/test/ui/type-sizes.rs b/src/test/ui/type-sizes.rs
index 3dfe0ad7f72c1..27433fd770b05 100644
--- a/src/test/ui/type-sizes.rs
+++ b/src/test/ui/type-sizes.rs
@@ -2,6 +2,7 @@
 
 #![allow(non_camel_case_types)]
 #![allow(dead_code)]
+#![feature(never_type)]
 
 use std::mem::size_of;
 
diff --git a/src/test/ui/uninhabited/uninhabited-irrefutable.rs b/src/test/ui/uninhabited/uninhabited-irrefutable.rs
index 84daa35484f81..48cd92719b49a 100644
--- a/src/test/ui/uninhabited/uninhabited-irrefutable.rs
+++ b/src/test/ui/uninhabited/uninhabited-irrefutable.rs
@@ -1,3 +1,4 @@
+#![feature(never_type)]
 #![feature(exhaustive_patterns)]
 
 mod foo {
diff --git a/src/test/ui/uninhabited/uninhabited-irrefutable.stderr b/src/test/ui/uninhabited/uninhabited-irrefutable.stderr
index 6ba03ee508316..26e1be34ea75d 100644
--- a/src/test/ui/uninhabited/uninhabited-irrefutable.stderr
+++ b/src/test/ui/uninhabited/uninhabited-irrefutable.stderr
@@ -1,5 +1,5 @@
 error[E0005]: refutable pattern in local binding: `A(_)` not covered
-  --> $DIR/uninhabited-irrefutable.rs:26:9
+  --> $DIR/uninhabited-irrefutable.rs:27:9
    |
 LL | / enum Foo {
 LL | |     A(foo::SecretlyEmpty),
diff --git a/src/test/ui/uninhabited/uninhabited-patterns.rs b/src/test/ui/uninhabited/uninhabited-patterns.rs
index 66a1a7f7735eb..1bf01184a08e7 100644
--- a/src/test/ui/uninhabited/uninhabited-patterns.rs
+++ b/src/test/ui/uninhabited/uninhabited-patterns.rs
@@ -1,5 +1,6 @@
 #![feature(box_patterns)]
 #![feature(box_syntax)]
+#![feature(never_type)]
 #![feature(exhaustive_patterns)]
 #![feature(slice_patterns)]
 #![deny(unreachable_patterns)]
diff --git a/src/test/ui/uninhabited/uninhabited-patterns.stderr b/src/test/ui/uninhabited/uninhabited-patterns.stderr
index 4a793c4510ec1..3e5329cfb3011 100644
--- a/src/test/ui/uninhabited/uninhabited-patterns.stderr
+++ b/src/test/ui/uninhabited/uninhabited-patterns.stderr
@@ -1,35 +1,35 @@
 error: unreachable pattern
-  --> $DIR/uninhabited-patterns.rs:26:9
+  --> $DIR/uninhabited-patterns.rs:27:9
    |
 LL |         &[..] => (),
    |         ^^^^^
    |
 note: lint level defined here
-  --> $DIR/uninhabited-patterns.rs:5:9
+  --> $DIR/uninhabited-patterns.rs:6:9
    |
 LL | #![deny(unreachable_patterns)]
    |         ^^^^^^^^^^^^^^^^^^^^
 
 error: unreachable pattern
-  --> $DIR/uninhabited-patterns.rs:31:9
+  --> $DIR/uninhabited-patterns.rs:32:9
    |
 LL |         Ok(box _) => (),
    |         ^^^^^^^^^
 
 error: unreachable pattern
-  --> $DIR/uninhabited-patterns.rs:33:9
+  --> $DIR/uninhabited-patterns.rs:34:9
    |
 LL |         Err(&[..]) => (),
    |         ^^^^^^^^^^
 
 error: unreachable pattern
-  --> $DIR/uninhabited-patterns.rs:40:9
+  --> $DIR/uninhabited-patterns.rs:41:9
    |
 LL |         Err(Ok(_y)) => (),
    |         ^^^^^^^^^^^
 
 error: unreachable pattern
-  --> $DIR/uninhabited-patterns.rs:43:15
+  --> $DIR/uninhabited-patterns.rs:44:15
    |
 LL |     while let Some(_y) = foo() {
    |               ^^^^^^^^