Move all tests using dart:io to a separate directory

tests/standalone/src/io/ProcessStderrTest.dart

Index: tests/standalone/src/io/ProcessStderrTest.dart
diff --git a/tests/standalone/src/ProcessStderrTest.dart b/tests/standalone/src/io/ProcessStderrTest.dart
similarity index 91%
rename from tests/standalone/src/ProcessStderrTest.dart
rename to tests/standalone/src/io/ProcessStderrTest.dart
index 6d75ede8b7752e0614a2a20c92325b7365831c4f..f8e8b0a3862c7a9add75d79730618b322089c0ee 100644
--- a/tests/standalone/src/ProcessStderrTest.dart
+++ b/tests/standalone/src/io/ProcessStderrTest.dart
@@ -9,7 +9,6 @@
 // VMOptions=--short_socket_write
 // VMOptions=--short_socket_read --short_socket_write
 
-#library("ProcessStderrTest");
 #import("dart:io");
 #source("ProcessTestUtil.dart");
 
@@ -63,9 +62,9 @@ main() {
 
   // Run the test using the dart binary with an echo script.
   // The test runner can be run from either the root or from runtime.
-  var scriptFile = new File("tests/standalone/src/ProcessStdIOScript.dart");
+  var scriptFile = new File("tests/standalone/src/io/ProcessStdIOScript.dart");
   if (!scriptFile.existsSync()) {
-    scriptFile = new File("../tests/standalone/src/ProcessStdIOScript.dart");
+    scriptFile = new File("../tests/standalone/src/io/ProcessStdIOScript.dart");
   }
   Expect.isTrue(scriptFile.existsSync());
   test(new Process.start(getDartFileName(), [scriptFile.name, "1"]), 0);