Stabilize ptr::{from_ref, from_mut}

Author: WaffleLapkin

library/core/src/ptr/mod.rs

@@ -708,7 +708,8 @@ where
 /// type or mutability, in particular if the code is refactored.
 #[inline(always)]
 #[must_use]
-#[unstable(feature = "ptr_from_ref", issue = "106116")]
+#[stable(feature = "ptr_from_ref", since = "CURRENT_RUSTC_VERSION")]
+#[rustc_const_stable(feature = "ptr_from_ref", since = "CURRENT_RUSTC_VERSION")]
 #[rustc_never_returns_null_ptr]
 #[rustc_diagnostic_item = "ptr_from_ref"]
 pub const fn from_ref<T: ?Sized>(r: &T) -> *const T {
@@ -721,7 +722,9 @@ pub const fn from_ref<T: ?Sized>(r: &T) -> *const T {
 /// type or mutability, in particular if the code is refactored.
 #[inline(always)]
 #[must_use]
-#[unstable(feature = "ptr_from_ref", issue = "106116")]
+#[stable(feature = "ptr_from_ref", since = "CURRENT_RUSTC_VERSION")]
+#[rustc_const_stable(feature = "ptr_from_ref", since = "CURRENT_RUSTC_VERSION")]
+#[rustc_allow_const_fn_unstable(const_mut_refs)]
 #[rustc_never_returns_null_ptr]
 pub const fn from_mut<T: ?Sized>(r: &mut T) -> *mut T {
     r