[clang] [compiler-rt] [llvm] Add numerical sanitizer (PR #85916)

[Alexander Shaposhnikov via cfe-commits]

alexander-shaposhnikov wrote:

@vitalybuka , @arsenm - thanks a lot, yeah, sure, I can split the patch.
P.S. will update/address comments soon.

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