Turn on dartc testing of tests/standalone.

tests/standalone/io/process_check_arguments_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:io";
-part "process_test_util.dart";
+import "process_test_util.dart";
 
 test(args) {
   var future = Process.start(new Options().executable, args);
   future.then((process) {
     process.onExit = (exitCode) {
       Expect.equals(0, exitCode);
     };
     // Drain stdout and stderr.
     process.stdout.onData = process.stdout.read;
     process.stderr.onData = process.stderr.read;
@@ skipping 12 matching lines @@
   test([scriptFile.name, '3', '0', 'a b']);
   test([scriptFile.name, '3', '0', 'a\tb']);
   test([scriptFile.name, '3', '1', 'a\tb"']);
   test([scriptFile.name, '3', '1', 'a"\tb']);
   test([scriptFile.name, '3', '1', 'a"\t\\\\"b"']);
   test([scriptFile.name, '4', '0', 'a\tb', 'a']);
   test([scriptFile.name, '4', '0', 'a\tb', 'a\t\t\t\tb']);
   test([scriptFile.name, '4', '0', 'a\tb', 'a    b']);
 }