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

src/math.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.
 
 var rngstate;  // Initialized to a Uint32Array during genesis.
 
 (function(global, utils) {
 "use strict";
 
 %CheckIsBootstrapping();
 
 // -------------------------------------------------------------------
 // Imports
 
 var GlobalMath = global.Math;
 var GlobalObject = global.Object;
 var InternalArray = utils.InternalArray;
+var toStringTagSymbol = utils.ImportNow("to_string_tag_symbol");
 
 //-------------------------------------------------------------------
 
 // ECMA 262 - 15.8.2.1
 function MathAbs(x) {
   x = +x;
   return (x > 0) ? x : 0 - x;
 }
 
 // ECMA 262 - 15.8.2.2
@@ skipping 253 matching lines @@
   var approx_hi = MathFloorJS(%_DoubleHi(x) / 3) + 0x2A9F7893;
   var approx = %_ConstructDouble(approx_hi, 0);
   approx = NEWTON_ITERATION_CBRT(x, approx);
   approx = NEWTON_ITERATION_CBRT(x, approx);
   approx = NEWTON_ITERATION_CBRT(x, approx);
   return NEWTON_ITERATION_CBRT(x, approx);
 }
 
 // -------------------------------------------------------------------
 
-%AddNamedProperty(GlobalMath, symbolToStringTag, "Math", READ_ONLY | DONT_ENUM);
+%AddNamedProperty(GlobalMath, toStringTagSymbol, "Math", READ_ONLY | DONT_ENUM);
 
 // Set up math constants.
 utils.InstallConstants(GlobalMath, [
   // ECMA-262, section 15.8.1.1.
   "E", 2.7182818284590452354,
   // ECMA-262, section 15.8.1.2.
   "LN10", 2.302585092994046,
   // ECMA-262, section 15.8.1.3.
   "LN2", 0.6931471805599453,
   // ECMA-262, section 15.8.1.4.
@@ skipping 54 matching lines @@
 utils.Export(function(to) {
   to.MathAbs = MathAbs;
   to.MathExp = MathExp;
   to.MathFloor = MathFloorJS;
   to.IntRandom = MathRandomRaw;
   to.MathMax = MathMax;
   to.MathMin = MathMin;
 });
 
 })