Use WeakCell to handle the script wrapper cache

src/factory.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/factory.h"
 
 #include "src/allocation-site-scopes.h"
 #include "src/base/bits.h"
 #include "src/conversions.h"
 #include "src/isolate-inl.h"
@@ skipping 819 matching lines @@
 
 
 Handle<Script> Factory::NewScript(Handle<String> source) {
   // Generate id for this script.
   Heap* heap = isolate()->heap();
   int id = heap->last_script_id()->value() + 1;
   if (!Smi::IsValid(id) || id < 0) id = 1;
   heap->set_last_script_id(Smi::FromInt(id));
 
   // Create and initialize script object.
-  Handle<Foreign> wrapper = NewForeign(0, TENURED);
   Handle<Script> script = Handle<Script>::cast(NewStruct(SCRIPT_TYPE));
   script->set_source(*source);
   script->set_name(heap->undefined_value());
   script->set_id(Smi::FromInt(id));
   script->set_line_offset(Smi::FromInt(0));
   script->set_column_offset(Smi::FromInt(0));
   script->set_context_data(heap->undefined_value());
   script->set_type(Smi::FromInt(Script::TYPE_NORMAL));
-  script->set_wrapper(*wrapper);
+  script->set_wrapper(heap->undefined_value());
   script->set_line_ends(heap->undefined_value());
   script->set_eval_from_shared(heap->undefined_value());
   script->set_eval_from_instructions_offset(Smi::FromInt(0));
   script->set_flags(Smi::FromInt(0));
 
   return script;
 }
 
 
 Handle<Foreign> Factory::NewForeign(Address addr, PretenureFlag pretenure) {
@@ skipping 1598 matching lines @@
   return Handle<Object>::null();
 }
 
 
 Handle<Object> Factory::ToBoolean(bool value) {
   return value ? true_value() : false_value();
 }
 
 
 } }  // namespace v8::internal