[heap] Fix verification of unsafe object layout changes.

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 <memory>
 
@@ skipping 1665 matching lines @@
   // new space, or if the value is an immortal immutable object, like the maps
   // of primitive (non-JS) objects like strings, heap numbers etc.
   inline void set_map_no_write_barrier(Map* value);
 
   // Get the map using acquire load.
   inline Map* synchronized_map();
   inline MapWord synchronized_map_word() const;
 
   // Set the map using release store
   inline void synchronized_set_map(Map* value);
-  inline void synchronized_set_map_no_write_barrier(Map* value);
   inline void synchronized_set_map_word(MapWord map_word);
 
+  // Initialize the map immediately after the object is allocated.
+  // Do not use this outside Heap.
+  inline void set_map_after_allocation(
+      Map* value, WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
+
   // During garbage collection, the map word of a heap object does not
   // necessarily contain a map pointer.
   inline MapWord map_word() const;
   inline void set_map_word(MapWord map_word);
 
   // The Heap the object was allocated in. Used also to access Isolate.
   inline Heap* GetHeap() const;
 
   // Convenience method to get current isolate.
   inline Isolate* GetIsolate() const;
@@ skipping 8516 matching lines @@
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #include "src/objects/object-macros-undef.h"
 
 #endif  // V8_OBJECTS_H_