[llvm] [LLVM][Instrumentation] Add numerical sanitizer (PR #85916)

[Alexander Shaposhnikov via llvm-commits]

alexander-shaposhnikov wrote:

Addressed comments, rebased the patch. @arsenm, @vitalybuka - happy to do more passes over it, otherwise maybe
we can try landing the patch / getting it through the build bots (this would unblock further progress).

https://github.com/llvm/llvm-project/pull/85916