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

[Vitaly Buka via cfe-commits]

vitalybuka wrote:

Can we split the patch into smaller pieces?
e.g. clang, transform, runtime ?

This one has transform, comments, so we can keep it for transform.


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