Get rid of more () in getter definitions.

tests/compiler/dart2js/cpa_inference_test.dart

 // Copyright (c) 2012, 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.
 
 import "dart:uri";
 import "../../../lib/compiler/implementation/elements/elements.dart";
 import '../../../lib/compiler/implementation/scanner/scannerlib.dart';
 import '../../../lib/compiler/implementation/source_file.dart';
 import '../../../lib/compiler/implementation/types/types.dart';
 import '../../../lib/compiler/implementation/tree/tree.dart';
@@ skipping 241 matching lines @@
   result.checkFieldHasType('A', 'x', [result.int, result.bool]);
   result.checkFieldHasType('A', 'y', [result.string, new NullBaseType()]);
   result.checkFieldHasType('A', 'z', [result.string]);
 }
 
 testGetters() {
   final String source = r"""
       class A {
         var x;
         A(this.x);
-        get y() => x;
+        get y => x;
       }
       main() {
         var a = new A(42);
         var foo = a.x;
         var bar = a.y;
         foo; bar;
       }
       """;
   AnalysisResult result = analyze(source);
   result.checkNodeHasType('foo', [result.int]);
@@ skipping 112 matching lines @@
   testMutuallyRecusiveFunction();
   testConstructor();
   testGetters();
   testSetters();
   testNamedParameters();
   testListLiterals();
   testMapLiterals();
   testReturn();
   // testNoReturn(); // right now we infer the empty type instead of null
 }