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

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 287f6bb2e1db6c644564602ef3f551d33a8bb877..7acb7489a0f58afdb3c01aab4deab3d6cf8d169e 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -2850,7 +2850,8 @@ class ArrayList : public FixedArray {
   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)