bors c8e94975a6 Auto merge of #90596 - the8472:path-hash-opt, r=Mark-Simulacrum
Optimize Eq and Hash for Path/PathBuf

```
# new

test path::tests::bench_hash_path_long                            ... bench:          86 ns/iter (+/- 1)
test path::tests::bench_hash_path_short                           ... bench:          13 ns/iter (+/- 1)
test path::tests::bench_path_hashset                              ... bench:         197 ns/iter (+/- 6)
test path::tests::bench_path_hashset_miss                         ... bench:          94 ns/iter (+/- 4)

# old

test path::tests::bench_hash_path_long                            ... bench:         192 ns/iter (+/- 2)
test path::tests::bench_hash_path_short                           ... bench:          33 ns/iter (+/- 1)
test path::tests::bench_path_hashset                              ... bench:       1,121 ns/iter (+/- 24)
test path::tests::bench_path_hashset_miss                         ... bench:         273 ns/iter (+/- 6)
```
2021-11-14 15:18:26 +00:00
..