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

[Alexander Shaposhnikov via llvm-commits]

================
@@ -1,19 +1,22 @@
 // RUN: %clangxx_nsan -O0 -g %s -o %t
 // RUN: NSAN_OPTIONS=check_nan=true,halt_on_error=0 %run %t 2>&1 | FileCheck %s
 
+// RUN: %clangxx_nsan -O3 -g %s -o %t
+// RUN: NSAN_OPTIONS=check_nan=true,halt_on_error=0 %run %t 2>&1 | FileCheck %s
+
----------------
alexander-shaposhnikov wrote:

let's add 
```
// RUN: NSAN_OPTIONS=check_nan=true,halt_on_error=1 not %run %t
```

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