[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 5a010b51c9ca899c5e8b1409b41d81851d9a979e..0c76ba0f6ae092054c96b30d5bb3c3edbb31a9dd 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -2852,7 +2852,8 @@ 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)