[compiler-rt] [compiler-rt][nsan] Add two steps in init process (PR #98807)

[Fangrui Song via llvm-commits]

https://github.com/MaskRay commented:

Disabling core dumps makes sense.

https://github.com/google/sanitizers/issues/637 describes why many sanitizers install signal handlers. But nsan doesn't deal with these undefined behaviors and perhaps doesn't need it? 

https://github.com/llvm/llvm-project/pull/98807