[libcxx-commits] [libcxx] [libc++] Add missing hardening checks and tests for vector<bool> (PR #121366)

[Konstantin Varlamov via libcxx-commits]

var-const wrote:

@winner245 This is awesome, thank you! Can you please also update [the docs](https://libcxx.llvm.org/Hardening.html#hardened-containers-status) to remove the note about `vector<bool>`?
```
Note: vector<bool> iterator is not currently hardened.
```

https://github.com/llvm/llvm-project/pull/121366