- Implement the old sweeper.

vm/freelist.h

 // Copyright (c) 2011, 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_FREELIST_H_
 #define VM_FREELIST_H_
 
 #include "vm/allocation.h"
 #include "vm/assert.h"
 #include "vm/raw_object.h"
@@ skipping 15 matching lines @@
   intptr_t Size() const {
     if (class_ == minimal_element_class_) {
       return kObjectAlignment;
     }
     ASSERT(class_ == element_class_);
     return *SizeAddress();
   }
 
   static FreeListElement* AsElement(uword addr, intptr_t size);
 
+  static bool IsSpecialClass(RawObject* raw_obj) {
+    return (raw_obj == minimal_element_class_) || (raw_obj == element_class_);
+  }
+
   static void InitOnce();
 
  private:
   // This layout mirrors the layout of RawObject.
   RawClass* class_;
   FreeListElement* next_;
 
   // Returns the address of the embedded size.
   intptr_t* SizeAddress() const {
     ASSERT(class_ == element_class_);
@@ skipping 39 matching lines @@
   void SplitElementAfterAndEnqueue(FreeListElement* element, intptr_t size);
 
   FreeListElement* free_lists_[kNumLists + 1];
 
   DISALLOW_COPY_AND_ASSIGN(FreeList);
 };
 
 }  // namespace dart
 
 #endif  // VM_FREELIST_H_