Auto merge of #41143 - stjepang:optimize-bool-fetch-nand, r=nagisa
Optimize AtomicBool::fetch_nand
This is an attempt to push the PR #40563 to completion.
Benchmark: [source](https://gist.github.com/stjepang/023f5025623f5474184f9f4dfd6379ae)
Improvement:
```
name old_ ns/iter new_ce_ ns/iter diff ns/iter diff %
1t 146,440 89,904 -56,536 -38.61%
2t 561,456 316,835 -244,621 -43.57%
4t 2,822,821 1,005,424 -1,817,397 -64.38%
```
r? @eddyb
cc @alexcrichton @nagisa