Fix a couple of bugs in handling of factory redirections.

dart/tests/language/const_factory_redirection_test.dart

Index: dart/tests/language/const_factory_redirection_test.dart
diff --git a/dart/tests/language/const_factory_redirection_test.dart b/dart/tests/language/const_factory_redirection_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..95c06908edb9ca561bce772e7614622d1b74e613
--- /dev/null
+++ b/dart/tests/language/const_factory_redirection_test.dart
@@ -0,0 +1,23 @@
+// 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.
+
+// Test that factory redirections work for compile-time constants, and
+// that abstract classes can redirect.
+
+abstract class C {
+  const factory C(int x) = D;
+}
+
+class D implements C {
+  final int i;
+  const D(this.i);
+}
+
+main() {
+  const C c = const C(42);
+  D d = c;
+  Expect.equals(42, d.i);
+  d = new C(42);
+  Expect.equals(42, d.i);
+}