Make objects embedded in optimized code weak.

src/handles.h

Index: src/handles.h
diff --git a/src/handles.h b/src/handles.h
index c3e4dca1a6e71e758255e9bcd182692edd4b9a07..35f9c93e36cf3ebb74bd991fc21a1ba685af38af 100644
--- a/src/handles.h
+++ b/src/handles.h
@@ -331,6 +331,11 @@ Handle<ObjectHashTable> PutIntoObjectHashTable(Handle<ObjectHashTable> table,
                                                Handle<Object> value);
 
 
+void AddWeakObjectToCodeDependency(Heap* heap,
+                                   Handle<Object> object,
+                                   Handle<Code> code);
+
+
 // Seal off the current HandleScope so that new handles can only be created
 // if a new HandleScope is entered.
 class SealHandleScope BASE_EMBEDDED {