Reduced TLS accesses even further.

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 211 matching lines @@
                             Handle<Object> prototype) {
   ASSERT(function->should_have_prototype());
   CALL_HEAP_FUNCTION(function->GetIsolate(),
                      Accessors::FunctionSetPrototype(*function,
                                                      *prototype,
                                                      NULL),
                      Object);
 }
 
 
-Handle<Object> SetProperty(Handle<Object> object,
+Handle<Object> SetProperty(Isolate* isolate,
+                           Handle<Object> object,
                            Handle<Object> key,
                            Handle<Object> value,
                            PropertyAttributes attributes,
                            StrictModeFlag strict_mode) {
-  Isolate* isolate = Isolate::Current();
   CALL_HEAP_FUNCTION(
       isolate,
       Runtime::SetObjectProperty(
           isolate, object, key, value, attributes, strict_mode),
       Object);
 }
 
 
 Handle<Object> ForceSetProperty(Handle<JSObject> object,
                                 Handle<Object> key,
@@ skipping 829 matching lines @@
   data->next = prev_next_;
   data->limit = prev_limit_;
 #ifdef DEBUG
   handles_detached_ = true;
 #endif
   return deferred;
 }
 
 
 } }  // namespace v8::internal