[libc-commits] [libc] [libc] Replace `MutexLock` with `cpp::lock_guard` (PR #89340)

[Nick Desaulniers via libc-commits]

nickdesaulniers wrote:

Yeah, then it's fine to mention in the PR description that you were inspired by libstdc++'s implementation.

https://github.com/llvm/llvm-project/pull/89340