[clang] [llvm] [AMDGPU] Implement 'llvm.get.fpenv' and 'llvm.set.fpenv' (PR #83906)

[Matt Arsenault via cfe-commits]

================
@@ -839,6 +839,18 @@ unsigned test_wavefrontsize() {
   return __builtin_amdgcn_wavefrontsize();
 }
 
+// CHECK-LABEL test_get_fpenv(
----------------
arsenm wrote:

It's a standard C concept. You need to enable #pragma STDC FENV_ACCESS ON to do anything valid with the floating point environment 

https://github.com/llvm/llvm-project/pull/83906