[AST][NFC] Pack CXXOperatorCallExpr

Use the space available in the bit-fields of Stmt.
This saves 8 bytes per CXXOperatorCallExpr. NFC.

llvm-svn: 349924
diff --git a/clang/lib/AST/ExprCXX.cpp b/clang/lib/AST/ExprCXX.cpp
index 3ddfbf1..a9fdb63 100644
--- a/clang/lib/AST/ExprCXX.cpp
+++ b/clang/lib/AST/ExprCXX.cpp
@@ -485,8 +485,13 @@
                                          FPOptions FPFeatures,
                                          ADLCallKind UsesADL)
     : CallExpr(CXXOperatorCallExprClass, Fn, /*PreArgs=*/{}, Args, Ty, VK,
-               OperatorLoc, /*MinNumArgs=*/0, UsesADL),
-      Operator(OpKind), FPFeatures(FPFeatures) {
+               OperatorLoc, /*MinNumArgs=*/0, UsesADL) {
+  CXXOperatorCallExprBits.OperatorKind = OpKind;
+  CXXOperatorCallExprBits.FPFeatures = FPFeatures.getInt();
+  assert((CXXOperatorCallExprBits.OperatorKind == OpKind) &&
+         "OperatorKind overflow!");
+  assert((CXXOperatorCallExprBits.FPFeatures == FPFeatures.getInt()) &&
+         "FPFeatures overflow!");
   Range = getSourceRangeImpl();
 }