Add test of unittests.

tests/compiler/dart2js/bad_output_io_test.dart

 // Copyright (c) 2013, 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 that the compiler can handle imports when package root has not been set.
 
-library dart2js.test.missing_file;
+library dart2js.test.bad_output_io;
 
 import 'dart:io' show exit;
 import 'package:expect/expect.dart';
 
 import 'package:compiler/compiler.dart'
        show Diagnostic;
 import 'package:compiler/src/dart2js.dart'
        show exitFunc, compileFunc, compile, diagnosticHandler;
 import 'package:compiler/src/source_file_provider.dart'
        show FormattingDiagnosticHandler;
@@ skipping 51 matching lines @@
     CollectingFormattingDiagnosticHandler handler = diagnosticHandler;
     Expect.equals(1, handler.messages.length);
     var message = handler.messages[0];
     Expect.isTrue(message[0].contains("Cannot open file"));
     Expect.equals(Diagnostic.ERROR, message[1]);
     Expect.equals(1, exitCode);
     exit(0);
   };
   compile(["foo.dart", "--out=bar.dart"]);
 }