[llvm] [LLVM][rtsan] Add LLVM nosanitize_realtime attribute (PR #105447)

[Chris Apple via llvm-commits]

cjappl wrote:

I also just recalled it was Vitaly that set us on the path of LLVM to begin with, see the discussion here:

https://github.com/llvm/llvm-project/pull/100192#discussion_r1688697745

https://github.com/llvm/llvm-project/pull/105447