[llvm] [LLVM][rtsan] Add nonblocking attribute for the realtime sanitizer (PR #100596)

[Nikita Popov via llvm-commits]

nikic wrote:

Can't say for sure without seeing the spec, but this is almost certainly the wrong name for the attribute. `nonblocking` would imply that "blocking" (for some rigorous definition thereof) is UB and LLVM can optimize with that knowledge. What you probably want is a `sanitize_realtime` attribute or something.

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