Fix merging of super type of classes

Forward declarations will not provide information about base types.
When base type information is available later, it must be merged.
An example of a (previously) missed super type is:
  class MM_Scavenger : public MM_Collector

Signed-off-by: Keith W. Campbell <keithc@ca.ibm.com>

ddr/lib/ddr-ir/Symbol_IR.cpp

@@ -334,6 +334,21 @@ MergeVisitor::visitComposite(ClassType *type) const
 DDR_RC
 MergeVisitor::visitClass(ClassUDT *type) const
 {
+	if (NULL == type->_superClass) {
+		ClassUDT *otherSuper = ((ClassUDT *)_other)->_superClass;
+
+		if (NULL != otherSuper) {
+			Type *thisSuper = _ir->findTypeInMap(otherSuper);
+
+			if (NULL != thisSuper) {
+				otherSuper = (ClassUDT *)thisSuper;
+			} else {
+				_merged->push_back(otherSuper);
+			}
+			type->_superClass = otherSuper;
+		}
+	}
+
 	return visitComposite(type);
 }