Port and integrate the irregexp engine from V8

tests/language/regex/negative-special-characters_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 Unicode in negative RegExp character classes."
+  );
+
+  dynamic testPassed(str) { }
+  dynamic testFailed(str) => Expect.fail(str);
+
+  dynamic test(pattern, str, expected_length) {
+    var result = str.replaceAll(new RegExp(pattern, caseSensitive: false, multiLine: true), '');
+
+    if (result.length == expected_length)
+      testPassed('"' + pattern + '", ' + '"' + str + '".');
+    else
+      testFailed('"' + pattern + '", ' + '"' + str + '". Was "' + result + '".');
+  }
+
+
+  test("\\s", " \t\f\v\r\n", 0); // ASCII whitespace.
+  test("\\S", "Проверка", 0); // Cyrillic letters are non-whitespace...
+  test("\\s", "Проверка", 8); // ...and they aren't whitespace.
+  test("[\\s]", "Проверка", 8);
+  test("[\\S]", "Проверка", 0);
+  test("[^\\s]", "Проверка", 0);
+  test("[^\\S]", "Проверка", 8);
+  test("[\\s\\S]*", "\\u2002Проверка\\r\\n\\u00a0", 0);
+  test("\\S\\S", "уф", 0);
+  test("\\S{2}", "уф", 0);
+
+  test("\\w", "Проверка", 8); // Alas, only ASCII characters count as word ones in JS.
+  test("\\W", "Проверка", 0);
+  test("[\\w]", "Проверка", 8);
+  test("[\\W]", "Проверка", 0);
+  test("[^\\w]", "Проверка", 0);
+  test("[^\\W]", "Проверка", 8);
+  test("\\W\\W", "уф", 0);
+  test("\\W{2}", "уф", 0);
+
+  test("\\d", "Проверка", 8); // Digit and non-digit.
+  test("\\D", "Проверка", 0);
+  test("[\\d]", "Проверка", 8);
+  test("[\\D]", "Проверка", 0);
+  test("[^\\d]", "Проверка", 0);
+  test("[^\\D]", "Проверка", 8);
+  test("\\D\\D", "уф", 0);
+  test("\\D{2}", "уф", 0);
+
+  test("[\\S\\d]", "Проверка123", 0);
+  test("[\\d\\S]", "Проверка123", 0);
+  test("[^\\S\\d]", "Проверка123", 11);
+  test("[^\\d\\S]", "Проверка123", 11);
+
+  test("[ \\S]", " Проверка ", 0);
+  test("[\\S ]", " Проверка ", 0);
+  test("[ф \\S]", " Проверка ", 0);
+  test("[\\Sф ]", " Проверка ", 0);
+
+  test("[^р\\S]", " Проверка ", 8);
+  test("[^\\Sр]", " Проверка ", 8);
+  test("[^р\\s]", " Проверка ", 4);
+  test("[^\\sр]", " Проверка ", 4);
+
+  test("[ф \\s\\S]", "Проверка \\r\\n", 0);
+  test("[\\S\\sф ]", "Проверка \\r\\n", 0);
+
+  test("[^z]", "Проверка \\r\\n", 0);
+  test("[^ф]", "Проверка \\r\\n", 0);
+}