[builtins] Unify most of the remaining Math builtins.

src/js/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
@@ skipping 345 matching lines @@
 function NumberIsNaN(number) {
   return IS_NUMBER(number) && NUMBER_IS_NAN(number);
 }
 
 
 // Harmony isSafeInteger
 function NumberIsSafeInteger(number) {
   if (NumberIsFinite(number)) {
     var integral = TO_INTEGER(number);
     if (integral == number) {
-      return %math_abs(integral) <= kMaxSafeInteger;
+      return -kMaxSafeInteger <= integral && integral <= kMaxSafeInteger;
     }
   }
   return false;
 }
 
 
 // ----------------------------------------------------------------------------
 
 %FunctionSetPrototype(GlobalNumber, new GlobalNumber(0));
 
@@ skipping 72 matching lines @@
   to.NumberIsNaN = NumberIsNaN;
   to.NumberIsInteger = NumberIsInteger;
   to.ObjectHasOwnProperty = GlobalObject.prototype.hasOwnProperty;
 });
 
 %InstallToContext([
   "object_value_of", ObjectValueOf,
 ]);
 
 })