Implement `String.prototype.codePointAt` and `String.fromCodePoint`

test/mjsunit/harmony/string-fromcodepoint.js

 // Copyright 2014 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.
 
 // Flags: --harmony-strings
 
 // Tests taken from:
-// https://github.com/mathiasbynens/String.fromCodePoint/blob/master/tests/tests.js
+// https://github.com/mathiasbynens/String.fromCodePoint
 
-assertEquals(String.fromCodePoint.length, 0);
+assertEquals(String.fromCodePoint.length, 1);
 assertEquals(String.propertyIsEnumerable("fromCodePoint"), false);
 
 assertEquals(String.fromCodePoint(""), "\0");
 assertEquals(String.fromCodePoint(), "");
 assertEquals(String.fromCodePoint(-0), "\0");
 assertEquals(String.fromCodePoint(0), "\0");
 assertEquals(String.fromCodePoint(0x1D306), "\uD834\uDF06");
 assertEquals(
     String.fromCodePoint(0x1D306, 0x61, 0x1D307),
     "\uD834\uDF06a\uD834\uDF07");
@@ skipping 16 matching lines @@
 assertThrows(function() { String.fromCodePoint(/./); }, RangeError);
 assertThrows(function() { String.fromCodePoint({
   valueOf: function() { throw Error(); } });
 }, Error);
 assertThrows(function() { String.fromCodePoint({
   valueOf: function() { throw Error(); } });
 }, Error);
 var tmp = 0x60;
 assertEquals(String.fromCodePoint({
   valueOf: function() { ++tmp; return tmp; }
 }), "a");

[arv, 2014/06/19 22:24:44]

Assert tmp here too (and in the other file)

+assertEquals(tmp, 0x61);
 
 var counter = Math.pow(2, 15) * 3 / 2;
 var result = [];
 while (--counter >= 0) {
   result.push(0); // one code unit per symbol
 }
 String.fromCodePoint.apply(null, result); // must not throw
 
 var counter = Math.pow(2, 15) * 3 / 2;
 var result = [];
 while (--counter >= 0) {
   result.push(0xFFFF + 1); // two code units per symbol
 }
 String.fromCodePoint.apply(null, result); // must not throw