Unify processing of weak lists in heap.cc

src/runtime.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 672 matching lines @@
   array_buffer->set_flag(Smi::FromInt(0));
   array_buffer->set_is_external(is_external);
 
   Handle<Object> byte_length =
       isolate->factory()->NewNumberFromSize(allocated_length);
   CHECK(byte_length->IsSmi() || byte_length->IsHeapNumber());
   array_buffer->set_byte_length(*byte_length);
 
   array_buffer->set_weak_next(isolate->heap()->array_buffers_list());
   isolate->heap()->set_array_buffers_list(*array_buffer);
-  array_buffer->set_weak_first_array(Smi::FromInt(0));
+  array_buffer->set_weak_first_array(isolate->heap()->undefined_value());
 }
 
 
 bool Runtime::SetupArrayBufferAllocatingData(
     Isolate* isolate,
     Handle<JSArrayBuffer> array_buffer,
     size_t allocated_length) {
   void* data;
   if (allocated_length != 0) {
     data = malloc(allocated_length);
@@ skipping 12927 matching lines @@
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(Heap::kNoGCFlags,
                                        "Runtime::PerformGC");
   }
 }
 
 
 } }  // namespace v8::internal