[compiler-rt] [compiler-rt][nsan] Add support for nan detection (PR #101531)

[Alexander Shaposhnikov via llvm-commits]

alexander-shaposhnikov wrote:

@cseslowpoke, let's try to complete this effort:
0. Make sure halt_on_error works (see comments above)
1. Update tests (see inline comments)
2. Test halt_on_erro=1 and test -O3

https://github.com/llvm/llvm-project/pull/101531