Rollup of 22 pull requests

Successful merges:

 - #128666 (Add `overflow_checks` intrinsic)
 - #146305 (Add correct suggestion for multi-references for self type in method)
 - #147179 ([DebugInfo] Fix container types failing to find template args)
 - #147743 (Show packed field alignment in mir_transform_unaligned_packed_ref)
 - #148079 (Rename `downcast_[ref|mut]_unchecked` -> `downcast_unchecked_[ref|mut]`)
 - #148084 (Optimize path components iteration on platforms that don't have prefixes)
 - #148126 (Fix rust stdlib build failing for VxWorks)
 - #148204 (Modify contributor email entries in .mailmap)
 - #148279 (rustc_builtin_macros: rename bench parameter to avoid collisions with user-defined function names)
 - #148333 (constify result unwrap unchecked)
 - #148539 (Add Allocator proxy impls for Box, Rc, and Arc)
 - #148601 (`invalid_atomic_ordering`: also lint `update` & `try_update`)
 - #148612 (Add note for identifier with attempted hygiene violation)
 - #148613 (Switch hexagon targets to rust-lld)
 - #148619 (Enable std locking functions on AIX)
 - #148644 ([bootstrap] Make `--open` option work with `doc src/tools/error_index_generator`)
 - #148649 (don't completely reset `HeadUsages`)
 - #148673 (Remove a remnant of `dyn*` from the parser)
 - #148675 (Remove eslint-js from npm dependencies)
 - #148680 (Recover `[T: N]` as `[T; N]`)
 - #148688 (Remove unused argument `features` from `eval_config_entry`)
 - #148711 (Use the current lint note id when parsing `cfg!()`)

r? `@ghost`
`@rustbot` modify labels: rollup

Rollup merge of #148084 - the8472:prefixless-path-components-iter, r=Mark-Simulacrum

Optimize path components iteration on platforms that don't have prefixes

```
OLD

path::bench_path_components_iter 140.20ns/iter +/- 6.08
path::bench_path_file_name 57.62ns/iter +/- 1.62

NEW

path::bench_path_components_iter 126.74ns/iter +/- 1.46
path::bench_path_file_name 47.48ns/iter +/- 2.49
```

…-iter, r=Mark-Simulacrum

Optimize path components iteration on platforms that don't have prefixes

```
OLD

path::bench_path_components_iter 140.20ns/iter +/- 6.08
path::bench_path_file_name 57.62ns/iter +/- 1.62

NEW

path::bench_path_components_iter 126.74ns/iter +/- 1.46
path::bench_path_file_name 47.48ns/iter +/- 2.49
```

…-iter, r=Mark-Simulacrum

Optimize path components iteration on platforms that don't have prefixes

```
OLD

path::bench_path_components_iter 140.20ns/iter +/- 6.08
path::bench_path_file_name 57.62ns/iter +/- 1.62

NEW

path::bench_path_components_iter 126.74ns/iter +/- 1.46
path::bench_path_file_name 47.48ns/iter +/- 2.49
```