[clang] [NFC][analyzer] Replace BlockInCriticalSection MutexDescriptor with C… (PR #224230)

[Balázs Benics via cfe-commits]

https://github.com/steakhal approved this pull request.

LGTM. This looks a lot more conventional.
Have a look at the tiny nits inline before merging.

https://github.com/llvm/llvm-project/pull/224230