Move Null class out of the VM isolate.

runtime/vm/raw_object.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/raw_object.h"
 
 #include "vm/class_table.h"
 #include "vm/freelist.h"
 #include "vm/isolate.h"
 #include "vm/object.h"
 #include "vm/visitor.h"
 
 
 namespace dart {
 
 bool RawObject::IsVMHeapObject() const {
   // TODO(asiva): Need a better way to represent VM heap objects, for
   // now we use the premarked property for identifying objects in the
   // VM heap.
   ASSERT(IsHeapObject());
   ASSERT(!Isolate::Current()->heap()->gc_in_progress());
   return IsMarked();
 }
 
 
 void RawObject::Validate(Isolate* isolate) const {
-  if (Object::null_class_ == reinterpret_cast<RawClass*>(kHeapObjectTag)) {
+  if (Object::void_class_ == reinterpret_cast<RawClass*>(kHeapObjectTag)) {
     // Validation relies on properly initialized class classes. Skip if the
     // VM is still being initialized.
     return;
   }
   // All Smi values are valid.
   if (!IsHeapObject()) {
     return;
   }
   // Validate that the tags_ field is sensible.
   uword tags = ptr()->tags_;
@@ skipping 772 matching lines @@
 
 intptr_t RawMirrorReference::VisitMirrorReferencePointers(
     RawMirrorReference* raw_obj, ObjectPointerVisitor* visitor) {
   // Make sure that we got here with the tagged pointer as this.
   ASSERT(raw_obj->IsHeapObject());
   visitor->VisitPointers(raw_obj->from(), raw_obj->to());
   return MirrorReference::InstanceSize();
 }
 
 }  // namespace dart