[clang] [flang] [mlir] [flang,acc] Support -ffp-maxmin-behavior option in lowering. (PR #184730)

[Tarun Prabhu via cfe-commits]

================
@@ -7646,6 +7646,17 @@ def J : JoinedOrSeparate<["-"], "J">,
 
 let Visibility = [FC1Option] in {
 
+def ffp_maxmin_behavior_EQ
+    : Joined<["-"], "ffp-maxmin-behavior=">,
+      Flags<[HelpHidden]>,
+      Group<f_Group>,
+      Values<"legacy,portable,extremum,extremenum">,
+      HelpText<"Control MAX/MIN and [max|min][loc|val] behavior: "
----------------
tarunprabhu wrote:

It might be good to keep consistent casing here. 

```suggestion
      HelpText<"Control max/min and [max|min][loc|val] behavior: "
```

https://github.com/llvm/llvm-project/pull/184730