Support runtime check of function types.

tests/language/function_subtype_setter0_test.dart

Index: tests/language/function_subtype_setter0_test.dart
diff --git a/tests/language/function_subtype_setter0_test.dart b/tests/language/function_subtype_setter0_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..7f48f1b1dac21eeb3268ceef73a74d20d6d30593
--- /dev/null
+++ b/tests/language/function_subtype_setter0_test.dart
@@ -0,0 +1,40 @@
+// 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 function subtyping for implicit setters.
+
+import 'package:expect/expect.dart';
+
+typedef void Foo();
+class A<T> {}
+
+class C {
+  Foo foo;
+  A<int> bar;
+}
+
+class D {
+  Foo foo;
+  A<int> bar;
+}
+
+test(var c) {
+  bool inCheckedMode = false;
+  try {
+    var x = 42;
+    String a = x;
+  } catch (e) {
+    inCheckedMode = true;
+  }
+  if (inCheckedMode) {
+    Expect.throws(() => c.foo = 1, (e) => true);
+  }
+  c.foo = () {};
+}
+
+void main() {
+  test(new C());
+  test(new D());
+}