Harmony: move math features to es-staging.

test/mjsunit/es6/math-log2-log10.js

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 27 matching lines @@
   assertEquals("-Infinity", String(fun(0)));
   assertEquals("-Infinity", String(fun(-0)));
   assertEquals(0, fun(1));
   assertEquals("Infinity", String(fun(Infinity)));
 });
 
 for (var i = -300; i < 300; i += 0.7) {
   assertEqualsDelta(i, Math.log10(Math.pow(10, i)), 1E-13);
   assertEqualsDelta(i, Math.log2(Math.pow(2, i)), 1E-13);
 }