Native context: do not put public symbols and flags on the js builtins object.

src/iterator-prototype.js

Index: src/iterator-prototype.js
diff --git a/src/iterator-prototype.js b/src/iterator-prototype.js
index 96dd7bfde1886cb4aa497735efad7230733f29bf..2f49d90b1c97baa9fd39723f5e559e426843bc07 100644
--- a/src/iterator-prototype.js
+++ b/src/iterator-prototype.js
@@ -9,13 +9,14 @@ var $iteratorPrototype;
   %CheckIsBootstrapping();
 
   var GlobalObject = global.Object;
+  var iteratorSymbol = utils.ImportNow("iterator_symbol");
 
   // 25.1.2.1 %IteratorPrototype% [ @@iterator ] ( )
   function IteratorPrototypeIterator() {
     return this;
   }
 
-  utils.SetFunctionName(IteratorPrototypeIterator, symbolIterator);
-  %AddNamedProperty($iteratorPrototype, symbolIterator,
+  utils.SetFunctionName(IteratorPrototypeIterator, iteratorSymbol);
+  %AddNamedProperty($iteratorPrototype, iteratorSymbol,
       IteratorPrototypeIterator, DONT_ENUM);
 })