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

src/v8natives.js

 // Copyright 2012 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.
 
 (function(global, utils) {
 
 %CheckIsBootstrapping();
 
 // ----------------------------------------------------------------------------
 // Imports
 
+var FLAG_harmony_tostring;
 var GlobalArray = global.Array;
 var GlobalBoolean = global.Boolean;
 var GlobalFunction = global.Function;
 var GlobalNumber = global.Number;
 var GlobalObject = global.Object;
 var InternalArray = utils.InternalArray;
+var iteratorSymbol = utils.ImportNow("iterator_symbol");
 var MathAbs;
 var ProxyDelegateCallAndConstruct;
 var ProxyDerivedHasOwnTrap;
 var ProxyDerivedKeysTrap;
 var StringIndexOf;
-var ToBoolean;
-var ToNumber;
+var ToBoolean = utils.ImportNow("ToBoolean");
+var ToNumber = utils.ImportNow("ToNumber");
 var ToString;
+var toStringTagSymbol = utils.ImportNow("to_string_tag_symbol");
 
 utils.Import(function(from) {
   MathAbs = from.MathAbs;
   StringIndexOf = from.StringIndexOf;
   ToString = from.ToString;
 });
 
-utils.ImportNow(function(from) {
-  ToBoolean = from.ToBoolean;
-  ToNumber = from.ToNumber;
-});
-
 utils.ImportFromExperimental(function(from) {
+  FLAG_harmony_tostring = from.FLAG_harmony_tostring;
   ProxyDelegateCallAndConstruct = from.ProxyDelegateCallAndConstruct;
   ProxyDerivedHasOwnTrap = from.ProxyDerivedHasOwnTrap;
   ProxyDerivedKeysTrap = from.ProxyDerivedKeysTrap;
 });
 
 // ----------------------------------------------------------------------------
 
 
 // ECMA 262 - 15.1.4
 function GlobalIsNaN(number) {
@@ skipping 92 matching lines @@
 
 // ECMA-262 - 15.2.4.2
 function ObjectToString() {
   if (IS_UNDEFINED(this)) return "[object Undefined]";
   if (IS_NULL(this)) return "[object Null]";
   var O = TO_OBJECT(this);
   var builtinTag = %_ClassOf(O);
   var tag;
 
   // TODO(caitp): cannot wait to get rid of this flag :>
-  if (harmony_tostring) {
-    tag = O[symbolToStringTag];
+  if (FLAG_harmony_tostring) {
+    tag = O[toStringTagSymbol];
     if (!IS_STRING(tag)) {
       tag = builtinTag;
     }
   } else {
     tag = builtinTag;
   }
 
   return `[object ${tag}]`;
 }
 
@@ skipping 1603 matching lines @@
   "toString", FunctionToString
 ]);
 
 // ----------------------------------------------------------------------------
 // Iterator related spec functions.
 
 // ES6 rev 33, 2015-02-12
 // 7.4.1 GetIterator ( obj, method )
 function GetIterator(obj, method) {
   if (IS_UNDEFINED(method)) {
-    method = obj[symbolIterator];
+    method = obj[iteratorSymbol];
   }
   if (!IS_SPEC_FUNCTION(method)) {
     throw MakeTypeError(kNotIterable, obj);
   }
   var iterator = %_CallFunction(obj, method);
   if (!IS_SPEC_OBJECT(iterator)) {
     throw MakeTypeError(kNotAnIterator, iterator);
   }
   return iterator;
 }
@@ skipping 23 matching lines @@
 });
 
 %InstallToContext([
   "global_eval_fun", GlobalEval,
   "object_define_own_property", DefineOwnPropertyFromAPI,
   "object_get_own_property_descriptor", ObjectGetOwnPropertyDescriptor,
   "to_complete_property_descriptor", ToCompletePropertyDescriptor,
 ]);
 
 })