drop interalization of strings entering global constant slots

src/lookup.h

 // 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.
 
 #ifndef V8_LOOKUP_H_
 #define V8_LOOKUP_H_
 
 #include "src/factory.h"
 #include "src/isolate.h"
 #include "src/objects.h"
@@ skipping 124 matching lines @@
   }
   FieldIndex GetFieldIndex() const;
   Handle<HeapType> GetFieldType() const;
   int GetAccessorIndex() const;
   int GetConstantIndex() const;
   Handle<PropertyCell> GetPropertyCell() const;
   Handle<Object> GetAccessors() const;
   Handle<Object> GetDataValue() const;
   // Usually returns the value that was passed in, but may perform
   // non-observable modifications on it, such as internalize strings.
-  Handle<Object> WriteDataValue(Handle<Object> value);
+  void WriteDataValue(Handle<Object> value);
   void InternalizeName();
 
  private:
   enum class InterceptorState {
     kUninitialized,
     kSkipNonMasking,
     kProcessNonMasking
   };
 
   Handle<Map> GetReceiverMap() const;
@@ skipping 54 matching lines @@
   Handle<JSReceiver> holder_;
   Handle<Map> holder_map_;
   const Handle<JSReceiver> initial_holder_;
   int number_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_LOOKUP_H_