Catch errors for any new item, not just trait implementations

This matches the previous behavior of everybody_loops and is also more
consistent than special-casing impls.

Author: jyn514

src/librustc_resolve/late.rs

@@ -407,7 +407,10 @@ struct LateResolutionVisitor<'a, 'b, 'ast> {
 impl<'a, 'ast> Visitor<'ast> for LateResolutionVisitor<'a, '_, 'ast> {
     fn visit_item(&mut self, item: &'ast Item) {
         let prev = replace(&mut self.diagnostic_metadata.current_item, Some(item));
+        // Always report errors in items we just entered.
+        let old_ignore = replace(&mut self.in_func_body, false);
         self.resolve_item(item);
+        self.in_func_body = old_ignore;
         self.diagnostic_metadata.current_item = prev;
     }
     fn visit_arm(&mut self, arm: &'ast Arm) {
@@ -1174,8 +1177,6 @@ impl<'a, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
         impl_items: &'ast [P<AssocItem>],
     ) {
         debug!("resolve_implementation");
-        // Never ignore errors in trait implementations.
-        let old_ignore = replace(&mut self.in_func_body, false);
         // If applicable, create a rib for the type parameters.
         self.with_generic_param_rib(generics, ItemRibKind(HasGenericParams::Yes), |this| {
             // Dummy self type for better errors if `Self` is used in the trait path.
@@ -1271,7 +1272,6 @@ impl<'a, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
                 });
             });
         });
-        self.in_func_body = old_ignore;
     }
 
     fn check_trait_item<F>(&mut self, ident: Ident, ns: Namespace, span: Span, err: F)

src/test/rustdoc-ui/impl-fn-nesting.rs

@@ -41,8 +41,8 @@ pub fn f<B: UnknownBound>(a: UnknownType, b: B) {
             can_define_macros_here_too!();
 
             /// This also is documented.
-            pub fn doubly_nested(c: UnknownTypeShouldBeIgnored) {
-
+            pub fn doubly_nested(c: UnknownType) {
+            //~^ ERROR cannot find type `UnknownType` in this scope
             }
         }
     }

src/test/rustdoc-ui/impl-fn-nesting.stderr

@@ -52,9 +52,15 @@ error[E0412]: cannot find type `UnknownType` in this scope
 LL |         type Item = UnknownType;
    |                     ^^^^^^^^^^^ not found in this scope
 
+error[E0412]: cannot find type `UnknownType` in this scope
+  --> $DIR/impl-fn-nesting.rs:44:37
+   |
+LL |             pub fn doubly_nested(c: UnknownType) {
+   |                                     ^^^^^^^^^^^ not found in this scope
+
 error: Compilation failed, aborting rustdoc
 
-error: aborting due to 10 previous errors
+error: aborting due to 11 previous errors
 
 Some errors have detailed explanations: E0405, E0412.
 For more information about an error, try `rustc --explain E0405`.