Migrated test block 24 to Dart 2.0.

tests/corelib_2/regexp/regress-regexp-construct-result_test.dart

 // Copyright (c) 2014, the Dart project authors. All rights reserved.
 // Copyright 2013 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
@@ skipping 30 matching lines @@
     regexp_string += "|(b)";
   }
   var regexp = new RegExp(regexp_string);
 
   for (var i = 0; i < 10; i++) {
     var matches = regexp.firstMatch("a");
     var count = 0;
     assertEquals(num_captures + 1, matches.groupCount + 1);
   }
 }