Implement dynamic function checks.

dart/tests/language/type_variable_function_type_test.dart

Index: dart/tests/language/type_variable_function_type_test.dart
diff --git a/dart/tests/language/type_variable_function_type_test.dart b/dart/tests/language/type_variable_function_type_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..6c2d51586eea2697d2ab5c3112a76d0b98076d68
--- /dev/null
+++ b/dart/tests/language/type_variable_function_type_test.dart
@@ -0,0 +1,25 @@
+// Copyright (c) 2013, 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.
+
+import 'package:expect/expect.dart';
+
+typedef T Func<T>();
+
+class Foo<S> {
+  m(x) => x is Func<S>;
+}
+
+class Bar<T> {
+  f() {
+    T local() {}
+    return local;
+  }
+}
+
+void main() {
+  var x = new Foo<List<String>>();
+  if (new DateTime.now().millisecondsSinceEpoch == 42) x = new Foo<int>();
+  Expect.isFalse(x.m(new Bar<String>().f()));
+  Expect.isTrue(x.m(new Bar<List<String>>().f()));
+}