Port and integrate the irregexp engine from V8

tests/language/regex/extended-characters-more_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() {
+  description(
+  "This test checks a few cases of extended (> 127) characters in repeat regular expressions."
+  );
+
+  assertEquals("foo\u00a0\u00a0\u00a0".replaceFirst(new RegExp(new String.fromCharCode(0x00a0) + "*"), ""), "foo\u00a0\u00a0\u00a0");
+  assertEquals("foo\u00a0\u00a0\u00a0".replaceFirst(new RegExp(r"\u00a0+"), ""), "foo");
+  assertEquals("foo\u00a0\u00a0\u00a0".replaceFirst(new RegExp(r"\u00a0*$"), ""), "foo");
+}