Fix rust-lang#83613.

…ou-se

Add strong_count mutation methods to Rc

The corresponding methods were stabilized on `Arc` in rust-lang#79285 (tracking: rust-lang#71983). This patch implements and stabilizes identical methods on the `Rc` types as well.

Do not emit the advanced diagnostics on macros

Fixes rust-lang#83510

…cros, r=varkor

Trigger `unused_doc_comments` on macros at once

Fixes rust-lang#83768

Use AnonConst for asm! constants

This replaces the old system which used explicit promotion. See rust-lang#83169 for more background.

The syntax for `const` operands is still the same as before: `const <expr>`.

Fixes rust-lang#83169

Because the implementation is heavily based on inline consts, we suffer from the same issues:
- We lose the ability to use expressions derived from generics. See the deleted tests in `src/test/ui/asm/const.rs`.
- We are hitting the same ICEs as inline consts, for example rust-lang#78174. It is unlikely that we will be able to stabilize this before inline consts are stabilized.

… r=varkor

forbid `impl Trait` in generic param defaults

Fixes rust-lang#83929

Forbid using `impl Trait` in the default types of generic parameters, e.g. `struct Foo<T = impl Trait>`. I assume this was never supposed to be allowed - it seems no UI test used it.

Note that using `impl Trait` in this position did not hit a feature gate error; however, this *shouldn't* be a breaking change as any attempt to use it should have hit the ICE in rust-lang#83929 and/or failed to provide a defining use of the `impl Trait`.

…ascii, r=Manishearth

Disable using non-ascii identifiers in extern blocks.

Fixes rust-lang#83923.

Add suggestion to reborrow mutable references when they're moved in a for loop

Address rust-lang#83924

Do not ICE when closure is involved in Trait Alias Impl Trait

Fix rust-lang#83613.