[llvm] [LLVM][rtsan] Add nonblocking Attribute and RealtimeSanitizer pass (PR #100596)

[Vitaly Buka via llvm-commits]

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

LGTM but better to move transforms and CODE_OWNERS into separate patches


https://github.com/llvm/llvm-project/pull/100596