Lazily register prototype users

test/cctest/test-heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 5351 matching lines @@
   TestRightTrimFixedTypedArray(i::kExternalUint32Array, 8, 6);
   TestRightTrimFixedTypedArray(i::kExternalUint32Array, 8 - 1, 6);
 
   // 32-bit cases.
   TestRightTrimFixedTypedArray(i::kExternalUint8Array, 16, 3);
   TestRightTrimFixedTypedArray(i::kExternalUint8Array, 16 - 3, 3);
   TestRightTrimFixedTypedArray(i::kExternalUint16Array, 8, 3);
   TestRightTrimFixedTypedArray(i::kExternalUint16Array, 8 - 1, 3);
   TestRightTrimFixedTypedArray(i::kExternalUint32Array, 4, 3);
 }
+
+
+TEST(WeakFixedArray) {
+  CcTest::InitializeVM();
+  v8::HandleScope scope(CcTest::isolate());
+
+  Handle<HeapNumber> number = CcTest::i_isolate()->factory()->NewHeapNumber(1);
+  Handle<WeakFixedArray> array = WeakFixedArray::Add(Handle<Object>(), number);
+  array->Remove(number);
+  array->Compact();
+  WeakFixedArray::Add(array, number);
+}