fixup! isDynamicClass instead of isPolymorphic; add test

Author: Michael137

clang/lib/CodeGen/ABIInfoImpl.cpp

@@ -330,7 +330,7 @@ bool CodeGen::isEmptyRecordForLayout(const ASTContext &Context, QualType T) {
 
   // If this is a C++ record, check the bases first.
   if (const CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(RD)) {
-    if (CXXRD->isPolymorphic())
+    if (CXXRD->isDynamicClass())
       return false;
 
     for (const auto &I : CXXRD->bases())