Auto merge of #67104 - Centril:rollup-07vahh9, r=Centril

Rollup of 10 pull requests

Successful merges:

 - #66606 (Add feature gate for mut refs in const fn)
 - #66841 (Add `{f32,f64}::approx_unchecked_to<Int>` unsafe methods)
 - #67009 (Emit coercion suggestions in more places)
 - #67052 (Ditch `parse_in_attr`)
 - #67071 (Do not ICE on closure typeck)
 - #67078 (accept union inside enum if not followed by identifier)
 - #67090 (Change "either" to "any" in Layout::from_size_align's docs)
 - #67092 (Fix comment typos in src/libcore/alloc.rs)
 - #67094 (get rid of __ in field names)
 - #67102 (Add note to src/ci/docker/README.md about multiple docker images)

Failed merges:

 - #67101 (use `#[allow(unused_attributes)]` to paper over incr.comp problem)

r? @ghost