Revert "Support runtime check of function types."

tests/language/function_subtype_not0_test.dart

Index: tests/language/function_subtype_not0_test.dart
diff --git a/tests/language/function_subtype_not0_test.dart b/tests/language/function_subtype_not0_test.dart
deleted file mode 100644
index 7b8d8643602662122fd2faa2b7a5392716836ddb..0000000000000000000000000000000000000000
--- a/tests/language/function_subtype_not0_test.dart
+++ /dev/null
@@ -1,20 +0,0 @@
-// 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.
-// Dart test program for constructors and initializers.
-
-// Check negative function subtyping tests.
-
-import 'package:expect/expect.dart';
-
-typedef void Foo<T>(T t);
-typedef void Bar(int i);
-
-void bar(int i) {}
-
-void main() {
-  Expect.isFalse(bar is! Foo);
-  Expect.isTrue(bar is! Foo<bool>);
-  Expect.isFalse(bar is! Foo<int>);
-  Expect.isFalse(bar is! Bar);
-}