8003720: NPG: Method in interpreter stack frame can be deallocated

Pass down a closure during root scanning to keep the class of the method alive.

Reviewed-by: coleenp, jcoomes

hotspot/src/share/vm/memory/iterator.cpp

@@ -30,6 +30,10 @@ void KlassToOopClosure::do_klass(Klass* k) {
   k->oops_do(_oop_closure);
 }
 
+void CLDToOopClosure::do_cld(ClassLoaderData* cld) {
+  cld->oops_do(_oop_closure, &_klass_closure, _must_claim_cld);
+}
+
 void ObjectToOopClosure::do_object(oop obj) {
   obj->oop_iterate(_cl);
 }