Fix static warning in test:

tests/isolate/scenarios/automatic_resolution_root/package_resolve_test.dart

 // Copyright (c) 2015, 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:io';
 import 'dart:isolate';
 
 final PACKAGE_URI = "package:foo/bar.dart";
 
-void main([args, port]) async {
+main([args, port]) async {
   if (port != null) {
     testPackageResolution(port);
     return;
   }
   var p = new RawReceivePort();
   Isolate.spawnUri(Platform.script,
                    [],
                    p.sendPort,
                    automaticPackageResolution: true);
   p.handler = (msg) {
@@ skipping 25 matching lines @@
     var resolvedPkg = await Isolate.resolvePackageUri(Uri.parse(PACKAGE_URI));
     print("Spawned isolate's package root flag: $packageRootStr");
     print("Spawned isolate's package config flag: $packageConfigStr");
     print("Spawned isolate's loaded package root: $packageRoot");
     print("Spawned isolate's resolved package path: $resolvedPkg");
     port.send([packageRoot?.toString(), resolvedPkg?.toString()]);
   } catch (e, s) {
     port.send("$e\n$s\n");
   }
 }