[heap] Filter out stale left-trimmed handles for scavenges

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 "src/assert-scope.h"
@@ skipping 1473 matching lines @@
   // View this map word as a map pointer.
   inline Map* ToMap();
 
 
   // Scavenge collection: the map word of live objects in the from space
   // contains a forwarding address (a heap object pointer in the to space).
 
   // True if this map word is a forwarding address for a scavenge
   // collection.  Only valid during a scavenge collection (specifically,
   // when all map words are heap object pointers, i.e. not during a full GC).
-  inline bool IsForwardingAddress() const;
+  inline bool IsForwardingAddress();
 
   // Create a map word from a forwarding address.
   static inline MapWord FromForwardingAddress(HeapObject* object);
 
   // View this map word as a forwarding address.
   inline HeapObject* ToForwardingAddress();
 
   static inline MapWord FromRawValue(uintptr_t value) {
     return MapWord(value);
   }
@@ skipping 9410 matching lines @@
     }
     return value;
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_