Enable weak embedded objects in optimized code with a fix for heap verifier.

src/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 6868 matching lines @@
 
 
 MaybeObject* Heap::AddWeakObjectToCodeDependency(Object* obj,
                                                  DependentCode* dep) {
   ASSERT(!InNewSpace(obj));
   ASSERT(!InNewSpace(dep));
   MaybeObject* maybe_obj =
       WeakHashTable::cast(weak_object_to_code_table_)->Put(obj, dep);
   WeakHashTable* table;
   if (!maybe_obj->To(&table)) return maybe_obj;
+  if (ShouldZapGarbage() && weak_object_to_code_table_ != table) {
+    WeakHashTable::cast(weak_object_to_code_table_)->Zap(the_hole_value());
+  }
   set_weak_object_to_code_table(table);
   ASSERT_EQ(dep, WeakHashTable::cast(weak_object_to_code_table_)->Lookup(obj));
   return weak_object_to_code_table_;
 }
 
 
 DependentCode* Heap::LookupWeakObjectToCodeDependency(Object* obj) {
   Object* dep = WeakHashTable::cast(weak_object_to_code_table_)->Lookup(obj);
   if (dep->IsDependentCode()) return DependentCode::cast(dep);
   return DependentCode::cast(empty_fixed_array());
@@ skipping 1000 matching lines @@
   if (FLAG_concurrent_recompilation) {
     heap_->relocation_mutex_->Lock();
 #ifdef DEBUG
     heap_->relocation_mutex_locked_by_optimizer_thread_ =
         heap_->isolate()->optimizing_compiler_thread()->IsOptimizerThread();
 #endif  // DEBUG
   }
 }
 
 } }  // namespace v8::internal