Redirection type of a redirecting factory can be deferred

tests/language/regress_23408_test.dart

+// Copyright (c) 2015, 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.
+
+library regress_23408_test;
+
+import 'package:expect/expect.dart';
+
+import 'regress_23408_lib.dart' deferred as lib;
+
+class A<T> extends C {
+  get t => "$T";
+}
+
+class C {
+  var v = 55;
+  C();
+  factory C.c() = lib.K;
+  factory C.l() = A<lib.K>;
+}
+
+void main() {
+  var a = new C.l(); // Redirects to A<dynamic>
+  Expect.equals("dynamic", a.t);
+  Expect.throws(() => new C.c());
+  lib.loadLibrary().then((_) {
+    var b = new C.l(); // Still redirects to A<dynamic>
+    Expect.equals("dynamic", b.t);
+    var z = new C.c();
+    Expect.equals(55, z.v);
+  });
+}