Always visit object class from VisitReferences

We don't want to unload classes which have instances.

Slight increase in CMS GC time from ~6.5s to ~7.3s on
EvaluateAndApplyChanges.

Bug: 22720414
Change-Id: I467ff9c9d55163d2a90b999aef3bdd7b3f648bac
diff --git a/runtime/mirror/object.cc b/runtime/mirror/object.cc
index df680b5..4d94130 100644
--- a/runtime/mirror/object.cc
+++ b/runtime/mirror/object.cc
@@ -85,7 +85,7 @@
     // object above, copy references fields one by one again with a
     // RB. TODO: Optimize this later?
     CopyReferenceFieldsWithReadBarrierVisitor visitor(dest);
-    src->VisitReferences<true>(visitor, visitor);
+    src->VisitReferences(visitor, visitor);
   }
   gc::Heap* heap = Runtime::Current()->GetHeap();
   // Perform write barriers on copied object references.