[clang] [Clang] Add diagnostic when scoped enumeration requires an explicit conversion for binary operations (PR #152698)

[Timothy Choi via cfe-commits]

================
@@ -10772,9 +10811,14 @@ QualType Sema::CheckMultiplyDivideOperands(ExprResult &LHS, ExprResult &RHS,
   if (LHS.isInvalid() || RHS.isInvalid())
     return QualType();
 
-
-  if (compType.isNull() || !compType->isArithmeticType())
-    return InvalidOperands(Loc, LHS, RHS);
+  if (compType.isNull() || !compType->isArithmeticType()) {
+    InvalidOperands(Loc, LHS, RHS);
+    diagnoseScopedEnums(*this, Loc, LHS, RHS,
+                        IsCompAssign ? IsDiv ? BO_DivAssign : BO_MulAssign
+                        : IsDiv      ? BO_Div
+                                     : BO_Mul);
----------------
tinnamchoi wrote:

Would it be acceptable to change `CheckMultiplyDivideOperands` to take `BinaryOperatorKind Opc` instead of `bool IsCompAssign, bool IsDiv`? It should be even cleaner but I was trying to avoid changing existing function signatures. A lot of these `Check[Operation]Operands` functions have similar inconsistencies where sometimes they take a `BinaryOperatorKind`, `bool`s, or nothing at all. Maybe this can do with a bit of refactoring in the future.

https://github.com/llvm/llvm-project/pull/152698