Add support for the new function-type syntax.

tests/language/generic_function_typedef2_test.dart

+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file

[ahe, 2017/04/27 13:28:15]

:-)

[floitsch, 2017/04/27 13:30:14]

done in https://codereview.chromium.org/2849523002

+// 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 for a function type test that cannot be eliminated at compile time.
+
+import "package:expect/expect.dart";
+
+class A {}
+
+typedef int F();
+
+typedef G = F; /// 00: compile-time error
+typedef H = int; /// 01: compile-time error
+typedef I = A; /// 02: compile-time error
+typedef J = List<int>; /// 03: compile-time error
+typedef K = Function(Function<A>(A
+    <int>  /// 04: static type warning
+    ));
+typedef L = Function({
+  /*   /// 05: compile-time error
+  bool
+  */   /// 05: compile-time error
+  x});
+
+typedef M = Function({
+  /*   /// 06: compile-time error
+  bool
+  */   /// 06: compile-time error
+  int});
+
+foo({bool int}) {}
+main() {
+  bool b = true;
+  Expect.isFalse(b is G);  /// 00: continued
+  Expect.isFalse(b is H);  /// 01: continued
+  Expect.isFalse(b is I);  /// 02: continued
+  Expect.isFalse(b is J);  /// 03: continued
+  Expect.isFalse(b is K);  /// 04: continued
+  Expect.isFalse(b is L);
+  Expect.isFalse(b is M);
+  Expect.isTrue(foo is M);
+}