Port and integrate the irregexp engine from V8

tests/language/regex/ascii-regexp-subject_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.
+
+/**
+* @fileoverview Check that an initial ^ will result in a faster match fail.
+*/
+
+import 'util.dart';
+import 'package:expect/expect.dart';
+
+void main() {
+  var s = "foo";
+  var i;
+
+  for (i = 0; i < 18; i++) {
+    s = s + s;
+  }
+
+  dynamic repeatRegexp(re) {
+    for (i = 0; i < 1000; i++) {
+      re.hasMatch(s);
+    }
+  }
+
+  repeatRegexp(new RegExp(r"^bar"));
+  repeatRegexp(new RegExp(r"^foo|^bar|^baz"));
+  repeatRegexp(new RegExp(r"(^bar)"));
+  repeatRegexp(new RegExp(r"(?=^bar)\w+"));
+}