Use NumberIsNaN in collections.js and make it inlined

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.
 
 // This file relies on the fact that the following declarations have been made
 // in runtime.js:
 // var $Object = global.Object;
 // var $Boolean = global.Boolean;
 // var $Number = global.Number;
 // var $Function = global.Function;
@@ skipping 1697 matching lines @@
 
   // Harmony Number constructor additions
   InstallFunctions($Number, DONT_ENUM, $Array(
     "isFinite", NumberIsFinite,
     "isInteger", NumberIsInteger,
     "isNaN", NumberIsNaN,
     "isSafeInteger", NumberIsSafeInteger,
     "parseInt", GlobalParseInt,
     "parseFloat", GlobalParseFloat
   ));
+
+  %SetInlineBuiltinFlag(NumberIsNaN);
 }
 
 SetUpNumber();
 
 
 // ----------------------------------------------------------------------------
 // Function
 
 function FunctionSourceString(func) {
   while (%IsJSFunctionProxy(func)) {
@@ skipping 163 matching lines @@
   }
   if (!IS_SPEC_FUNCTION(method)) {
     throw MakeTypeError('not_iterable', [obj]);
   }
   var iterator = %_CallFunction(obj, method);
   if (!IS_SPEC_OBJECT(iterator)) {
     throw MakeTypeError('not_an_iterator', [iterator]);
   }
   return iterator;
 }