Add a VM defined class MirrorReference as an opaque pointer for Dart code to VM internal objects.

runtime/vm/object.h

 // 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.
 
 #ifndef VM_OBJECT_H_
 #define VM_OBJECT_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 5812 matching lines @@
     raw_weak->ptr()->key_ = Object::null();
     raw_weak->ptr()->value_ = Object::null();
   }
 
  private:
   FINAL_HEAP_OBJECT_IMPLEMENTATION(WeakProperty, Instance);
   friend class Class;
 };
 
 
+class MirrorReference : public Instance {
+ public:
+  RawObject* referent() const {
+    return raw_ptr()->referent_;
+  }
+
+  void set_referent(const Object& referent) const {
+    StorePointer(&raw_ptr()->referent_, referent.raw());
+  }
+
+  static RawMirrorReference* New(Heap::Space space = Heap::kNew);
+
+  static intptr_t InstanceSize() {
+    return RoundedAllocationSize(sizeof(RawMirrorReference));
+  }
+
+ private:
+  FINAL_HEAP_OBJECT_IMPLEMENTATION(MirrorReference, Instance);
+  friend class Class;
+};
+
+
 // Breaking cycles and loops.
 RawClass* Object::clazz() const {
   uword raw_value = reinterpret_cast<uword>(raw_);
   if ((raw_value & kSmiTagMask) == kSmiTag) {
     return Smi::Class();
   }
   return Isolate::Current()->class_table()->At(raw()->GetClassId());
 }
 
 
@@ skipping 106 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_