Make objects embedded in optimized code weak.

src/handles.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 887 matching lines @@
       impl_->isolate()->handle_scope_data();
   data->next = prev_next_;
   data->limit = prev_limit_;
 #ifdef DEBUG
   handles_detached_ = true;
 #endif
   return deferred;
 }
 
 
+void AddWeakObjectToCodeDependency(Heap* heap,
+                                   Handle<Object> object,
+                                   Handle<Code> code) {
+  if (!heap->weak_object_to_code()->IsHashTable()) {
+    heap->set_weak_object_to_code(
+        *heap->isolate()->factory()->NewWeakHashTable(16));
+  }
+  Handle<DependentCode> dep(heap->LookupWeakObjectToCodeDependency(*object));
+  dep = DependentCode::Insert(dep, DependentCode::kWeaklyEmbeddedGroup, code);
+  CALL_HEAP_FUNCTION_VOID(heap->isolate(),
+                          heap->AddWeakObjectToCodeDependency(*object, *dep));
+}
+
+
 } }  // namespace v8::internal