Make objects embedded in optimized code weak.

src/serialize.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 817 matching lines @@
   isolate_->heap()->set_array_buffers_list(
       isolate_->heap()->undefined_value());
 
   // The allocation site list is build during root iteration, but if no sites
   // were encountered then it needs to be initialized to undefined.
   if (isolate_->heap()->allocation_sites_list() == Smi::FromInt(0)) {
     isolate_->heap()->set_allocation_sites_list(
         isolate_->heap()->undefined_value());
   }
 
+  isolate_->heap()->set_weak_object_to_code(
+      isolate_->heap()->undefined_value());
+
   // Update data pointers to the external strings containing natives sources.
   for (int i = 0; i < Natives::GetBuiltinsCount(); i++) {
     Object* source = isolate_->heap()->natives_source_cache()->get(i);
     if (!source->IsUndefined()) {
       ExternalAsciiString::cast(source)->update_data_cache();
     }
   }
 
   // Issue code events for newly deserialized code objects.
   LOG_CODE_EVENT(isolate_, LogCodeObjects());
@@ skipping 1008 matching lines @@
 
 bool SnapshotByteSource::AtEOF() {
   if (0u + length_ - position_ > 2 * sizeof(uint32_t)) return false;
   for (int x = position_; x < length_; x++) {
     if (data_[x] != SerializerDeserializer::nop()) return false;
   }
   return true;
 }
 
 } }  // namespace v8::internal