Added a factory test that fails in frog and dartc. Will add bug numbers to status file once the c...

tests/language/src/FactoryImplementationTest.dart

+// Copyright (c) 2011, 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.
+
+interface A factory B {
+  A(int x, int y);
+}
+
+interface X factory B {
+  X(int x, int y);
+}
+
+class XImpl implements X {
+  final int x;
+  final int y;
+  XImpl(this.x, this.y);
+}
+
+// new A invokes B constructor because B implements A.
+class B implements A {
+  final int x;
+  final int y;
+
+  B(this.x, this.y);
+  // This factory will never be invoked.
+  // TODO(ahe): Is this a compile time error?
+  factory A(int a, int b) {  return new B(0, 0); }
+
+  factory X(int a, int b) { return new XImpl(a * 10, b * 10); }
+}
+
+main() {
+  var a = new A(1, 2);
+  // Check that constructor B is invoked and not factory A.
+  Expect.equals(1, a.x);
+  Expect.equals(2, a.y);
+
+  var x = new X(11, 22);
+  // Check that factory is invoked.
+  Expect.equals(110, x.x);
+  Expect.equals(220, x.y);
+}