Remove support for 'argument definitions test' from dart2js.

tests/compiler/dart2js_extra/argument_definition_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.
-
-// Test parsing and resolution of argument definition test.
-
-int test(int a, {int b: 2, int c: 3}) {
-  int result = 0;
-  print(?b);
-  print(?result);  /// 01: compile-time error
-  print(?a);
-  print(?b);
-  print(?c);
-  {
-    var b;
-    ?b;  /// 02: compile-time error
-  }
-  print((!?a?!?b:!?c) == (?a??b:?c));
-  print(!?a?!?b:!?c == ?a??b:?c);
-}
-
-closure_test(int a, {int b: 2, int c: 3}) {
-  var x = 0;
-  return () {
-    int result = 0;
-    print(?b);
-    print(?result);  /// 03: compile-time error
-    print(?x);  /// 04: compile-time error
-    print(?a);
-    print(?b);
-    print(?c);
-    {
-      var b;
-      ?b;  /// 05: compile-time error
-    }
-    print((!?a?!?b:!?c) == (?a??b:?c));
-    print(!?a?!?b:!?c == ?a??b:?c);
-  };
-}
-
-main() {
-  test(1);
-  test(1, b: 2);
-  test(1, b: 2, c: 3);
-  test(1, c: 3);
-
-  closure_test(1)();
-  closure_test(1, b: 2)();
-  closure_test(1, b: 2, c: 3)();
-  closure_test(1, c: 3)();
-}