Rollup merge of #129401 - workingjubilee:partial-initialization-of-stabilization, r=dtolnay,joboet

Partially stabilize `feature(new_uninit)`

Finished comment period: https://github.com/rust-lang/rust/issues/63291#issuecomment-2183022955

The following API has been stabilized from https://github.com/rust-lang/rust/issues/63291

```rust
impl<T> Box<T> { pub fn new_uninit() -> Box<MaybeUninit<T>> {…} }
impl<T> Rc<T> { pub fn new_uninit() -> Rc<MaybeUninit<T>> {…} }
impl<T> Arc<T> { pub fn new_uninit() -> Arc<MaybeUninit<T>> {…} }

impl<T> Box<[T]> { pub fn new_uninit_slice(len: usize) -> Box<[MaybeUninit<T>]> {…} }
impl<T> Rc<[T]> { pub fn new_uninit_slice(len: usize) -> Rc<[MaybeUninit<T>]> {…} }
impl<T> Arc<[T]> { pub fn new_uninit_slice(len: usize) -> Arc<[MaybeUninit<T>]> {…} }

impl<T> Box<MaybeUninit<T>> { pub unsafe fn assume_init(self) -> Box<T> {…} }
impl<T> Box<[MaybeUninit<T>]> { pub unsafe fn assume_init(self) -> Box<[T]> {…} }
impl<T> Rc<MaybeUninit<T>> { pub unsafe fn assume_init(self) -> Rc<T> {…} }
impl<T> Rc<[MaybeUninit<T>]> { pub unsafe fn assume_init(self) -> Rc<[T]> {…} }
impl<T> Arc<MaybeUninit<T>> { pub unsafe fn assume_init(self) -> Arc<T> {…} }
impl<T> Arc<[MaybeUninit<T>]> { pub unsafe fn assume_init(self) -> Arc<[T]> {…} }
```

The remaining API is split between new issues
- `new_zeroed_alloc`: https://github.com/rust-lang/rust/issues/129396
- `box_uninit_write`: https://github.com/rust-lang/rust/issues/129397

All relevant code is thus either stabilized or split out of that issue, so this closes #63291 as, with the FCP concluded, that issue has served its purpose.

try-job: x86_64-rust-for-linux

1 files changed, 0 insertions, 1 deletions

diff --git a/compiler/rustc_middle/src/lib.rs b/compiler/rustc_middle/src/lib.rs
index ce330b4744b..32f79ff7234 100644
--- a/compiler/rustc_middle/src/lib.rs
+++ b/compiler/rustc_middle/src/lib.rs
@@ -53,7 +53,6 @@
 #![feature(min_specialization)]
 #![feature(negative_impls)]
 #![feature(never_type)]
-#![feature(new_uninit)]
 #![feature(ptr_alignment_type)]
 #![feature(rustc_attrs)]
 #![feature(rustdoc_internals)]