[clang] Add clang warning if fp exception functions are called without appropriate flags/pragmas (#128239) (PR #187860)

[Eli Friedman via cfe-commits]

================
@@ -0,0 +1,55 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -verify=c,expected -DWRONG_FEXCEPT_T %s -ast-dump | FileCheck %s --check-prefixes=CHECK1,CHECK2
----------------
efriedma-quic wrote:

The C++ run-lines aren't really doing anything useful here; probably fine to get rid of them.

https://github.com/llvm/llvm-project/pull/187860