[clang] [flang] [llvm] [flang][flang-rt] Add -ffpe-trap= to set the initial FP exception halting mode (PR #208828)

[Tarun Prabhu via cfe-commits]

================
@@ -971,6 +952,72 @@ static void addFloatingPointOptions(const Driver &D, const ArgList &Args,
     CmdArgs.push_back("-freciprocal-math");
 }
 
+// Add options related to IEEE Floating point modes
+//
+// Initial halting mode:
+// Validate -ffpe-trap= and forward it to -fc1. This is handled separately from
+// addFloatingPointOptions() on purpose: -ffpe-trap= is not part of the
----------------
tarunprabhu wrote:

nit

```suggestion
// Validate -ffpe-trap= and forward it to -fc1. This is handled separately from
// addFloatingPointOptions(): -ffpe-trap= is not part of the
```

https://github.com/llvm/llvm-project/pull/208828