Enable syntax-only support for generic functions by default.

tests/language/generic_methods_new_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 object creation. With
 /// '--generic-method-syntax', the type argument is available at runtime,
 /// but erased to `dynamic`.
 
 library generic_methods_new_test;
 
 import "package:expect/expect.dart";
 
@@ skipping 14 matching lines @@
   Expect.isTrue(c is C<int> && c is C<String>); // C<dynamic>.
   Expect.isTrue(i is List<String> && i is List<int>); // List<dynamic>.
   Expect.equals(c.e, 42);
   Expect.equals(i[0], "Hello!");
 
   Map m1 = f3<int>(1);
   Expect.isTrue(m1 is Map<int, String> && m1 is Map<String, String>);
   Expect.isFalse(m1 is Map<int, int>);
   Expect.equals('hi', m1[1]);
 }