Revert "Revert "Modify FPFeatures to use delta not absolute settings""

This reverts commit b55d723ed61052b77e720dcffecac43abe873186.
Reapply Modify FPFeatures to use delta not absolute settings

To solve https://bugs.llvm.org/show_bug.cgi?id=46166 where the
floating point settings in PCH files aren't compatible, rewrite
FPFeatures to use a delta in the settings rather than absolute settings.
With this patch, these floating point options can be benign.

Reviewers: rjmccall

Differential Revision: https://reviews.llvm.org/D81869
diff --git a/clang/lib/CodeGen/CGStmtOpenMP.cpp b/clang/lib/CodeGen/CGStmtOpenMP.cpp
index b380143..7904d4a 100644
--- a/clang/lib/CodeGen/CGStmtOpenMP.cpp
+++ b/clang/lib/CodeGen/CGStmtOpenMP.cpp
@@ -3328,11 +3328,11 @@
     // Generate condition for loop.
     BinaryOperator *Cond = BinaryOperator::Create(
         C, &IVRefExpr, &UBRefExpr, BO_LE, C.BoolTy, VK_RValue, OK_Ordinary,
-        S.getBeginLoc(), FPOptions(C.getLangOpts()));
+        S.getBeginLoc(), FPOptionsOverride());
     // Increment for loop counter.
     UnaryOperator *Inc = UnaryOperator::Create(
         C, &IVRefExpr, UO_PreInc, KmpInt32Ty, VK_RValue, OK_Ordinary,
-        S.getBeginLoc(), true, FPOptions(C.getLangOpts()));
+        S.getBeginLoc(), true, FPOptionsOverride());
     auto &&BodyGen = [CapturedStmt, CS, &S, &IV](CodeGenFunction &CGF) {
       // Iterate through all sections and emit a switch construct:
       // switch (IV) {