[builtins] Migrate StringFromCodePoint to C++.

src/js/string.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 729 matching lines @@
     return first;
   }
   var second = %_StringCharCodeAt(string, pos + 1);
   if (second < 0xDC00 || second > 0xDFFF) {
     return first;
   }
   return (first - 0xD800) * 0x400 + second + 0x2400;
 }
 
 
-// ES6 Draft 05-22-2014, section 21.1.2.2
-function StringFromCodePoint(_) {  // length = 1
-  "use strict";
-  var code;
-  var length = arguments.length;
-  var index;
-  var result = "";
-  for (index = 0; index < length; index++) {
-    code = arguments[index];
-    if (!%_IsSmi(code)) {
-      code = TO_NUMBER(code);
-    }
-    if (code < 0 || code > 0x10FFFF || code !== TO_INTEGER(code)) {
-      throw MakeRangeError(kInvalidCodePoint, code);
-    }
-    if (code <= 0xFFFF) {
-      result += %_StringCharFromCode(code);
-    } else {
-      code -= 0x10000;
-      result += %_StringCharFromCode((code >>> 10) & 0x3FF | 0xD800);
-      result += %_StringCharFromCode(code & 0x3FF | 0xDC00);
-    }
-  }
-  return result;
-}
-
-
 // -------------------------------------------------------------------
 // String methods related to templates
 
 // ES6 Draft 03-17-2015, section 21.1.2.4
 function StringRaw(callSite) {
   "use strict";
   var numberOfSubstitutions = arguments.length;
   var cooked = TO_OBJECT(callSite);
   var raw = TO_OBJECT(cooked.raw);
   var literalSegments = TO_LENGTH(raw.length);
   if (literalSegments <= 0) return "";
 
   var result = TO_STRING(raw[0]);
 
   for (var i = 1; i < literalSegments; ++i) {
     if (i < numberOfSubstitutions) {
       result += TO_STRING(arguments[i]);
     }
     result += TO_STRING(raw[i]);
   }
 
   return result;
 }
 
 // -------------------------------------------------------------------
 
 // Set up the non-enumerable functions on the String object.
 utils.InstallFunctions(GlobalString, DONT_ENUM, [
-  "fromCodePoint", StringFromCodePoint,
   "raw", StringRaw
 ]);
 
 // Set up the non-enumerable functions on the String prototype object.
 utils.InstallFunctions(GlobalString.prototype, DONT_ENUM, [
   "valueOf", StringValueOf,
   "toString", StringToString,
   "codePointAt", StringCodePointAt,
   "concat", StringConcat,
   "endsWith", StringEndsWith,
@@ skipping 40 matching lines @@
   to.StringLastIndexOf = StringLastIndexOf;
   to.StringMatch = StringMatchJS;
   to.StringReplace = StringReplace;
   to.StringSlice = StringSlice;
   to.StringSplit = StringSplitJS;
   to.StringSubstr = StringSubstr;
   to.StringSubstring = StringSubstring;
 });
 
 })