Avoid TLS accesses in Object::Lookup and Object::GetPrototype.

src/string-stream.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 515 matching lines @@
       return;
     }
     Add("/* warning: Invalid JSFunction object found */ ");
   }
 }
 
 
 void StringStream::PrintPrototype(JSFunction* fun, Object* receiver) {
   Object* name = fun->shared()->name();
   bool print_name = false;
-  Heap* heap = HEAP;
-  for (Object* p = receiver; p != heap->null_value(); p = p->GetPrototype()) {
+  Isolate* isolate = fun->GetIsolate();
+  for (Object* p = receiver;
+       p != isolate->heap()->null_value();
+       p = p->GetPrototype(isolate)) {
     if (p->IsJSObject()) {
       Object* key = JSObject::cast(p)->SlowReverseLookup(fun);
-      if (key != heap->undefined_value()) {
+      if (key != isolate->heap()->undefined_value()) {
         if (!name->IsString() ||
             !key->IsString() ||
             !String::cast(name)->Equals(String::cast(key))) {
           print_name = true;
         }
         if (name->IsString() && String::cast(name)->length() == 0) {
           print_name = false;
         }
         name = key;
       }
@@ skipping 32 matching lines @@
 
 // Only grow once to the maximum allowable size.
 char* NoAllocationStringAllocator::grow(unsigned* bytes) {
   ASSERT(size_ >= *bytes);
   *bytes = size_;
   return space_;
 }
 
 
 } }  // namespace v8::internal