Enable syntax-only support for generic functions by default.

tests/language/generic_methods_function_type_test.dart

 // Copyright (c) 2016, 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.
 //
-// DartOptions=--generic-method-syntax
 // VMOptions=--generic-method-syntax
 
 /// Dart test on the usage of method type arguments in a function typed
 /// parameter declaration.
 
 library generic_methods_function_type_test;
 
 import "package:expect/expect.dart";
 
 class C<V> {
   U m1<U>(U f(V v), V v) => f(v);
   V m2<U>(V f(U v), U u) => f(u);
 }
 
 main() {
   Expect.equals(new C<int>().m1<int>((x) => x, 10), 10);
   Expect.equals(new C<int>().m2<int>((x) => x, 20), 20);
 }