Don't try to get the mark bits of the one ptr filler object

src/heap/heap.cc

 // Copyright 2012 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.
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/base/bits.h"
 #include "src/base/once.h"
@@ skipping 6193 matching lines @@
  public:
   explicit UnreachableObjectsFilter(Heap* heap) : heap_(heap) {
     MarkReachableObjects();
   }
 
   ~UnreachableObjectsFilter() {
     heap_->mark_compact_collector()->ClearMarkbits();
   }
 
   bool SkipObject(HeapObject* object) {
+    if (object->IsFiller()) return true;
     MarkBit mark_bit = Marking::MarkBitFrom(object);
     return Marking::IsWhite(mark_bit);
   }
 
  private:
   class MarkingVisitor : public ObjectVisitor {
    public:
     MarkingVisitor() : marking_stack_(10) {}
 
     void VisitPointers(Object** start, Object** end) {
@@ skipping 694 matching lines @@
     *object_type = "CODE_TYPE";                                                \
     *object_sub_type = "CODE_AGE/" #name;                                      \
     return true;
     CODE_AGE_LIST_COMPLETE(COMPARE_AND_RETURN_NAME)
 #undef COMPARE_AND_RETURN_NAME
   }
   return false;
 }
 }  // namespace internal
 }  // namespace v8