Fix VM not accepting static methods for Isolate.spawn.

tests/isolate/static_function_lib.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.
+
+library static_function_testlib;
+
+// Used by static_function_test.dart.
+
+void function(port) { port.send("LIBTOP"); }
+void _function(port) { port.send("_LIBTOP"); }
+
+Function get privateFunction => _function;
+
+class C {
+  static void function(SendPort port) { port.send("LIB"); }
+  static void _function(SendPort port) { port.send("LIBPRIVATE"); }
+  static Function get privateFunction => _function;
+}
+
+Function get privateClassFunction => _C.function;
+Function get privateClassAndFunction => _C._function;
+
+class _C {
+  static void function(SendPort port) { port.send("_LIB"); }
+  static void _function(SendPort port) { port.send("_LIBPRIVATE"); }
+}