[clang] [Clang][Sema] Fix missing warning when comparing mismatched enums in … (PR #81418)

[via cfe-commits]

================
@@ -263,6 +263,14 @@ namespace {
   }
 }
 
+QualType Expr::getEnumCoercedType(const ASTContext &Ctx) const {
+  bool NotEnumType = dyn_cast<EnumType>(this->getType()) == nullptr;
+  if (NotEnumType)
----------------
Kupa-Martin wrote:

In C mode enumeration constants have integral type, so `getEnumConstantDecl()` might not return `nullptr` even if the expression doesnt have enum type.

https://github.com/llvm/llvm-project/pull/81418