Auto merge of rust-lang#116233 - DaniPopes:stabilize-const_maybe_uninit_assume_init_read, r=dtolnay

Stabilize `const_maybe_uninit_assume_init_read`

AFAICT the only reason this was not included in the `maybe_uninit_extra` stabilization was because `ptr::read` was unstable (rust-lang#92768 (comment)), which has since been stabilized in 1.71.

Needs a separate FCP from the [original `maybe_uninit_extra` one](rust-lang#63567 (comment)).

Tracking issue: rust-lang#63567

Author: bors

library/core/src/mem/maybe_uninit.rs

@@ -686,7 +686,10 @@ impl<T> MaybeUninit<T> {
     /// // they both get dropped!
     /// ```
     #[stable(feature = "maybe_uninit_extra", since = "1.60.0")]
-    #[rustc_const_unstable(feature = "const_maybe_uninit_assume_init_read", issue = "63567")]
+    #[rustc_const_stable(
+        feature = "const_maybe_uninit_assume_init_read",
+        since = "CURRENT_RUSTC_VERSION"
+    )]
     #[inline(always)]
     #[track_caller]
     pub const unsafe fn assume_init_read(&self) -> T {

library/core/tests/lib.rs

@@ -15,7 +15,6 @@
 #![feature(const_hash)]
 #![feature(const_heap)]
 #![feature(const_maybe_uninit_as_mut_ptr)]
-#![feature(const_maybe_uninit_assume_init_read)]
 #![feature(const_nonnull_new)]
 #![feature(const_pointer_byte_offsets)]
 #![feature(const_pointer_is_aligned)]