Port and integrate the irregexp engine from V8

tests/language/regex/regress-regexp-construct-result_test.dart

+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'util.dart';
+import 'package:expect/expect.dart';
+
+void main() {
+  // Create a huge regexp with many alternative capture groups, most of
+  // which do not capture anything, but the corresponding capture slot
+  // in the result object has to exist, even though filled with null.
+  // Having a large result array helps stressing GC.
+
+  var num_captures = 1000;
+  var regexp_string = "(a)";
+  for (var i = 0; i < num_captures - 1; i++) {
+    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);
+  }
+}