Adds `DartOptions` to generic method syntax tests.

tests/language/generic_local_functions_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
 
 /// Dart test verifying that the parser can handle type parameterization of
 /// local function declarations, and declarations of function parameters.
 
 library generic_functions_test;
 
 import "package:expect/expect.dart";
 
 // Declare a generic function parameter.
 String f(int g<X, Y>(Map<X, Y> arg)) => null;
 
 main() {
   // Declare a generic local function
   int h<X extends Y, Y>(Map<X, Y> arg) => null;
   // Pass a generic local function as an argument.
   f(h);
   // Pass a function expression as an argument.
   f(<X, Y super X>(Map<X, Y> arg) => 42);
 }