Reland [heap] Avoid the use of cells to point from code to new-space objects.

src/objects.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 
 #include "src/assert-scope.h"
@@ skipping 2835 matching lines @@
     kReloadLengthAfterAllocation,
   };
   static Handle<ArrayList> Add(Handle<ArrayList> array, Handle<Object> obj,
                                AddMode mode = kNone);
   static Handle<ArrayList> Add(Handle<ArrayList> array, Handle<Object> obj1,
                                Handle<Object> obj2, AddMode = kNone);
   inline int Length();
   inline void SetLength(int length);
   inline Object* Get(int index);
   inline Object** Slot(int index);
-  inline void Set(int index, Object* obj);
+  inline void Set(int index, Object* obj,
+                  WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
   inline void Clear(int index, Object* undefined);
   bool IsFull();
   DECLARE_CAST(ArrayList)
 
  private:
   static Handle<ArrayList> EnsureSpace(Handle<ArrayList> array, int length);
   static const int kLengthIndex = 0;
   static const int kFirstIndex = 1;
   DISALLOW_IMPLICIT_CONSTRUCTORS(ArrayList);
 };
@@ skipping 8009 matching lines @@
     }
     return value;
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_