Port regexp tests from V8 to Dart.

tests/corelib/regexp/alternative-length-miscalculation_test.dart

Index: tests/corelib/regexp/alternative-length-miscalculation_test.dart
diff --git a/tests/language/deferred_only_constant_test.dart b/tests/corelib/regexp/alternative-length-miscalculation_test.dart
similarity index 50%
copy from tests/language/deferred_only_constant_test.dart
copy to tests/corelib/regexp/alternative-length-miscalculation_test.dart
index e50d7ba6a1537a687787b7659fb528b57ce85746..4c532f9b2c7712f8bd29b21f538015ae8faf3107 100644
--- a/tests/language/deferred_only_constant_test.dart
+++ b/tests/corelib/regexp/alternative-length-miscalculation_test.dart
@@ -2,14 +2,17 @@
 // 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.
 
-// Testing import of only constants from a deferred library.
-
+import 'util.dart';
 import 'package:expect/expect.dart';
 
-import "deferred_only_constant_lib.dart" deferred as lib;
-
 void main() {
-  lib.loadLibrary().then((_) {
-    Expect.equals(lib.constant, const ["a", "b", "c"]);
-  });
-}
+  description(
+  "This page tests for length miscalculations in regular expression processing."
+  );
+
+  var re = new RegExp(r"b|[^b]");
+  assertEquals('a'.indexOf(re, 1), -1);
+
+  var re2 = new RegExp(r"[^a]|ab");
+  shouldBeFalse(re2.hasMatch(''));
+}