Introduce InternalPackedArray.

src/regexp.js

 // Copyright 2012 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 367 matching lines @@
   };
 }
 
 
 // Property of the builtins object for recording the result of the last
 // regexp match.  The property lastMatchInfo 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 indeces.  The array also contains
 // the subject string for the last successful match.
-var lastMatchInfo = new InternalArray(
+var lastMatchInfo = new InternalPackedArray(
     2,                 // REGEXP_NUMBER_OF_CAPTURES
     "",                // Last subject.
     void 0,            // Last input - settable with RegExpSetInput.
     0,                 // REGEXP_FIRST_CAPTURE + 0
     0                  // REGEXP_FIRST_CAPTURE + 1
 );
 
 // Override last match info with an array of actual substrings.
 // Used internally by replace regexp with function.
 // The array has the format of an "apply" argument for a replacement
@@ skipping 81 matching lines @@
 
   for (var i = 1; i < 10; ++i) {
     %DefineOrRedefineAccessorProperty($RegExp, '$' + i,
                                       RegExpMakeCaptureGetter(i), NoOpSetter,
                                       DONT_DELETE);
   }
   %ToFastProperties($RegExp);
 }
 
 SetUpRegExp();