Implement String.prototype.codePointAt and String.fromCodePoint.

src/messages.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.
 
 // -------------------------------------------------------------------
 
 var kMessages = {
   // Error
   cyclic_proto:                  ["Cyclic __proto__ value"],
   code_gen_from_strings:         ["%0"],
@@ skipping 95 matching lines @@
   typed_array_set_negative_offset:
                                  ["Start offset is negative"],
   invalid_data_view_offset:      ["Start offset is outside the bounds of the buffer"],
   invalid_data_view_length:      ["Invalid data view length"],
   invalid_data_view_accessor_offset:
                                  ["Offset is outside the bounds of the DataView"],
 
   stack_overflow:                ["Maximum call stack size exceeded"],
   invalid_time_value:            ["Invalid time value"],
   invalid_count_value:           ["Invalid count value"],
+  invalid_code_point:            ["Invalid code point ", "%0"],
   // ReferenceError
   invalid_lhs_in_assignment:     ["Invalid left-hand side in assignment"],
   invalid_lhs_in_for:            ["Invalid left-hand side in for-loop"],
   invalid_lhs_in_postfix_op:     ["Invalid left-hand side expression in postfix operation"],
   invalid_lhs_in_prefix_op:      ["Invalid left-hand side expression in prefix operation"],
   // SyntaxError
   paren_in_arg_string:           ["Function arg string contains parenthesis"],
   not_isvar:                     ["builtin %IS_VAR: not a variable"],
   single_function_literal:       ["Single function literal required"],
   invalid_regexp_flags:          ["Invalid flags supplied to RegExp constructor '", "%0", "'"],
@@ skipping 1156 matching lines @@
 function SetUpStackOverflowBoilerplate() {
   var boilerplate = MakeRangeError('stack_overflow', []);
 
   %DefineAccessorPropertyUnchecked(
       boilerplate, 'stack', StackTraceGetter, StackTraceSetter, DONT_ENUM);
 
   return boilerplate;
 }
 
 var kStackOverflowBoilerplate = SetUpStackOverflowBoilerplate();