[regexp] Turn last match info into a simple FixedArray

src/js/regexp.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) {
 
 'use strict';
 
 %CheckIsBootstrapping();
 
 // -------------------------------------------------------------------
 
-// Property of the builtins object for recording the result of the last
-// regexp match.  The property RegExpLastMatchInfo includes the matchIndices
-// array of the last successful regexp match (an array of start/end index
-// pairs for the match and all the captured substrings), the invariant is
-// that there are at least two capture indices.  The array also contains
-// the subject string for the last successful match.
-// We use a JSObject rather than a JSArray so we don't have to manually update
-// its length.
-var RegExpLastMatchInfo = {
-  REGEXP_NUMBER_OF_CAPTURES: 2,
-  REGEXP_LAST_SUBJECT:       "",
-  REGEXP_LAST_INPUT:         UNDEFINED,  // Settable with RegExpSetInput.
-  CAPTURE0:                  0,
-  CAPTURE1:                  0
-};
-
 // ES#sec-getsubstitution
 // GetSubstitution(matched, str, position, captures, replacement)
 // Expand the $-expressions in the string and return a new string with
 // the result.
 function GetSubstitution(matched, string, position, captures, replacement) {
   var matchLength = matched.length;
   var stringLength = string.length;
   var capturesLength = captures.length;
   var tailPos = position + matchLength;
   var result = "";
@@ skipping 66 matching lines @@
 
     // Append substring between the previous and the next $ character.
     if (next > pos) {
       result += %_SubString(replacement, pos, next);
     }
   }
   return result;
 }
 
 // -------------------------------------------------------------------
-
-%InstallToContext(["regexp_last_match_info", RegExpLastMatchInfo]);
-
-// -------------------------------------------------------------------
 // Exports
 
 utils.Export(function(to) {
   to.GetSubstitution = GetSubstitution;
 });
 
 })