Enable syntax-only support for generic functions by default.

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
 // VMOptions=--generic-method-syntax
 
 /// Dart test verifying that the parser can handle type parameterization of
 /// local function declarations, and declarations of function parameters.
 
 library generic_local_functions_test;
 
 import "package:expect/expect.dart";
 
 // Declare a generic function parameter.
 int f(Y g<X, Y>(Map<X, Y> arg, X x)) => g<int, int>(<int, int>{1: 42}, 1);
 
 main() {
   // Declare a generic local function
   Y h<X, Y>(Map<X, Y> m, X x) => m[x];
   // Pass a generic local function as an argument.
   Expect.equals(f(h), 42);
   // Pass a function expression as an argument.
   Expect.equals(f(<X, Y>(Map<X, Y> m, X x) => m[x]), 42);
 }