[heap] Iterate handles with special left-trim visitor

src/heap/heap-inl.h

Index: src/heap/heap-inl.h
diff --git a/src/heap/heap-inl.h b/src/heap/heap-inl.h
index 137be9865513dd4e7c8e61fb0bdb01dff953de48..a58a2b74b57ef28158422a7a8cf0b1bbe87bb670 100644
--- a/src/heap/heap-inl.h
+++ b/src/heap/heap-inl.h
@@ -482,31 +482,6 @@ void Heap::CopyBlock(Address dst, Address src, int byte_size) {
             static_cast<size_t>(byte_size / kPointerSize));
 }
 
-bool Heap::PurgeLeftTrimmedObject(Object** object) {
-  HeapObject* current = reinterpret_cast<HeapObject*>(*object);
-  const MapWord map_word = current->map_word();
-  if (current->IsFiller() && !map_word.IsForwardingAddress()) {
-#ifdef DEBUG
-    // We need to find a FixedArrayBase map after walking the fillers.
-    while (current->IsFiller()) {
-      Address next = reinterpret_cast<Address>(current);
-      if (current->map() == one_pointer_filler_map()) {
-        next += kPointerSize;
-      } else if (current->map() == two_pointer_filler_map()) {
-        next += 2 * kPointerSize;
-      } else {
-        next += current->Size();
-      }
-      current = reinterpret_cast<HeapObject*>(next);
-    }
-    DCHECK(current->IsFixedArrayBase());
-#endif  // DEBUG
-    *object = nullptr;
-    return true;
-  }
-  return false;
-}
-
 template <Heap::FindMementoMode mode>
 AllocationMemento* Heap::FindAllocationMemento(HeapObject* object) {
   // Check if there is potentially a memento behind the object. If