[heap] Clear out of live range remembered set slots in large objects.

src/heap/spaces.h

 // Copyright 2011 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_HEAP_SPACES_H_
 #define V8_HEAP_SPACES_H_
 
 #include <list>
 
 #include "src/allocation.h"
@@ skipping 979 matching lines @@
   inline LargePage* next_page() {
     return static_cast<LargePage*>(next_chunk());
   }
 
   inline void set_next_page(LargePage* page) { set_next_chunk(page); }
 
   // Uncommit memory that is not in use anymore by the object. If the object
   // cannot be shrunk 0 is returned.
   Address GetAddressToShrink();
 
+  void ClearOutOfLiveRangeSlots(Address free_start);
+
   // A limit to guarantee that we do not overflow typed slot offset in
   // the old to old remembered set.
   // Note that this limit is higher than what assembler already imposes on
   // x64 and ia32 architectures.
   static const int kMaxCodePageSize = 512 * MB;
 
  private:
   static inline LargePage* Initialize(Heap* heap, MemoryChunk* chunk,
                                       Executability executable, Space* owner);
 
@@ skipping 2137 matching lines @@
     count = 0;
   }
   // Must be small, since an iteration is used for lookup.
   static const int kMaxComments = 64;
 };
 #endif
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_SPACES_H_