Introduce class TypeRef in the VM to fully support recursive types.

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/dart.h"
 #include "vm/freelist.h"
 #include "vm/isolate.h"
@@ skipping 283 matching lines @@
 }
 
 
 intptr_t RawType::VisitTypePointers(
     RawType* raw_obj, ObjectPointerVisitor* visitor) {
   visitor->VisitPointers(raw_obj->from(), raw_obj->to());
   return Type::InstanceSize();
 }
 
 
+intptr_t RawTypeRef::VisitTypeRefPointers(
+    RawTypeRef* raw_obj, ObjectPointerVisitor* visitor) {
+  visitor->VisitPointers(raw_obj->from(), raw_obj->to());
+  return TypeRef::InstanceSize();
+}
+
+
 intptr_t RawTypeParameter::VisitTypeParameterPointers(
     RawTypeParameter* raw_obj, ObjectPointerVisitor* visitor) {
   visitor->VisitPointers(raw_obj->from(), raw_obj->to());
   return TypeParameter::InstanceSize();
 }
 
 
 intptr_t RawBoundedType::VisitBoundedTypePointers(
     RawBoundedType* raw_obj, ObjectPointerVisitor* visitor) {
   visitor->VisitPointers(raw_obj->from(), raw_obj->to());
@@ skipping 522 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