Implement redirecting constructors.

dart/tests/language/redirecting_factory_infinite_steps_test.dart

Index: dart/tests/language/redirecting_factory_infinite_steps_test.dart
diff --git a/dart/tests/language/redirecting_factory_infinite_steps_test.dart b/dart/tests/language/redirecting_factory_infinite_steps_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..b1ced1a3fbed607c8e704c8645f5a6382af71067
--- /dev/null
+++ b/dart/tests/language/redirecting_factory_infinite_steps_test.dart
@@ -0,0 +1,20 @@
+// Copyright (c) 2012, 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.
+
+// From Dart Language Specification, 0.12 M1, "7.6.2 Factories": It is
+// a compile-time error if a redirecting factory constructor does not
+// redirect to a non-redirecting factory constructor or to a
+// generative constructor in a finite number of steps.
+
+class Foo {
+  factory Foo() = Bar;
+}
+
+class Bar {
+  factory Bar() = Foo; /// 01: compile-time error
+}
+
+main() {
+  new Foo();
+}