A few more trivial write barrier calls.

Change-Id: I4b0f3c4347eed9a2e0a494ae1382065c026d5c40
diff --git a/src/object.h b/src/object.h
index b9cab1d..3d11009 100644
--- a/src/object.h
+++ b/src/object.h
@@ -2269,7 +2269,7 @@
         dst_offset = MemberOffset(dst_offset.Uint32Value() + sizeof(Object*));
       }
     }
-    // TODO: bulk write barrier
+    Heap::WriteBarrier(dst);
   }
 }