Rollup merge of #80886 - RalfJung:stable-raw-ref-macros, r=m-ou-se

Stabilize raw ref macros

This stabilizes `raw_ref_macros` (https://github.com/rust-lang/rust/issues/73394), which is possible now that https://github.com/rust-lang/rust/issues/74355 is fixed.

However, as I already said in https://github.com/rust-lang/rust/issues/73394#issuecomment-751342185, I am not particularly happy with the current names of the macros. So I propose we also change them, which means I am proposing to stabilize the following in `core::ptr`:
```rust
pub macro const_addr_of($e:expr) {
    &raw const $e
}

pub macro mut_addr_of($e:expr) {
    &raw mut $e
}
```

The macro name change means we need another round of FCP. Cc `````@rust-lang/libs`````
Fixes #73394

library/core/src/lib.rs

@@ -126,7 +126,6 @@
 #![feature(auto_traits)]
 #![feature(or_patterns)]
 #![feature(prelude_import)]
-#![feature(raw_ref_macros)]
 #![feature(repr_simd, platform_intrinsics)]
 #![feature(rustc_attrs)]
 #![feature(simd_ffi)]