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

src/heap/remembered-set.h

 // Copyright 2016 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_REMEMBERED_SET_H
 #define V8_REMEMBERED_SET_H
 
 #include "src/assembler.h"
 #include "src/heap/heap.h"
 #include "src/heap/slot-set.h"
@@ skipping 209 matching lines @@
     if (direction == OLD_TO_OLD) {
       chunk->AllocateTypedOldToOldSlots();
       return chunk->typed_old_to_old_slots();
     } else {
       chunk->AllocateTypedOldToNewSlots();
       return chunk->typed_old_to_new_slots();
     }
   }
 
   static bool IsValidSlot(Heap* heap, MemoryChunk* chunk, Object** slot);
+  static bool IsValidTypedSlot(Heap* heap, MemoryChunk* chunk, SlotType type,
+                               Address host_addr, Address slot);
 };
 
 class UpdateTypedSlotHelper {
  public:
   // Updates a cell slot using an untyped slot callback.
   // The callback accepts (Heap*, Object**) and returns SlotCallbackResult.
   template <typename Callback>
   static SlotCallbackResult UpdateCell(RelocInfo* rinfo, Callback callback) {
     DCHECK(rinfo->rmode() == RelocInfo::CELL);
     Object* cell = rinfo->target_cell();
@@ skipping 102 matching lines @@
     }
     UNREACHABLE();
     return REMOVE_SLOT;
   }
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_REMEMBERED_SET_H