Fix a number of issues with determining the type of stdio

tests/standalone/io/dart_std_io_pipe_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 a dart sub-process handling stdio with different types of
 // redirection.
 //
 // VMOptions=
 // VMOptions=--short_socket_read
 // VMOptions=--short_socket_write
@@ skipping 22 matching lines @@
 void test(String shellScript, String dartScript, String type, bool devNull) {
   Directory dir = new Directory("").createTempSync();
 
   // The shell script will run the dart executable passed with a
   // number of different redirections of stdio.
   String pipeOutFile = "${dir.path}/pipe";
   if (devNull) pipeOutFile = "/dev/null";
   String redirectOutFile = "${dir.path}/redirect";
   String executable = new Options().executable;
   List args =
-      [executable, dartScript, type, pipeOutFile, redirectOutFile];
+      [executable,
+       dartScript,
+       type,
+       pipeOutFile,
+       redirectOutFile,
+       devNull ? "terminal" : "file"];
   var future = Process.start(shellScript, args);
   future.then((process) {
     process.exitCode.then((exitCode) {
       Expect.equals(0, exitCode);
 
       // Check the expected file contents.
       if (type == "0") {
         if (devNull) {
           checkFileEmpty("${redirectOutFile}.stdout");
         } else {
@@ skipping 44 matching lines @@
   var os = Platform.operatingSystem;
   if (os == 'windows') return;
 
   // Get the shell script for testing the Standalone Dart VM with
   // piping and redirections of stdio.
   var shellScript = new File("tests/standalone/io/dart_std_io_pipe_test.sh");
   if (!shellScript.existsSync()) {
     shellScript = new File("../tests/standalone/io/dart_std_io_pipe_test.sh");
   }
   // Get the Dart script file which echoes stdin to stdout or stderr or both.
-  var scriptFile = new File("tests/standalone/io/process_std_io_script.dart");
+  var scriptFile = new File("tests/standalone/io/dart_std_io_pipe_script.dart");
   if (!scriptFile.existsSync()) {
-    scriptFile = new File("../tests/standalone/io/process_std_io_script.dart");
+    scriptFile =
+        new File("../tests/standalone/io/dart_std_io_pipe_script.dart");
   }
 
   // Run the shell script.
   test(shellScript.path, scriptFile.path, "0", false);
   test(shellScript.path, scriptFile.path, "0", true);
   test(shellScript.path, scriptFile.path, "1", false);
   test(shellScript.path, scriptFile.path, "1", true);
   test(shellScript.path, scriptFile.path, "2", false);
   test(shellScript.path, scriptFile.path, "2", true);
 }