Remove DirectoryException and LinkException from dart:io and use FileException instaed.

tests/standalone/io/async_catch_errors_test.dart

Index: tests/standalone/io/async_catch_errors_test.dart
diff --git a/tests/standalone/io/async_catch_errors_test.dart b/tests/standalone/io/async_catch_errors_test.dart
index 0a9568da11fde6bc4a8621de77f28d7b77b8c7a4..4ebccb63d70c5c29d93ade34f1036a5a798b0c39 100644
--- a/tests/standalone/io/async_catch_errors_test.dart
+++ b/tests/standalone/io/async_catch_errors_test.dart
@@ -24,14 +24,14 @@ Future testSocketException() {
   return completer.future;
 }
 
-Future testFileException() {
+Future testFileSystemException() {
   var completer = new Completer();
   runZoned(() {
     new File("lol it's not a file\n").openRead().listen(null);
   }, onError: (err) {
-    if (err is! FileException) Expect.fail("Not expected error: $err");
+    if (err is! FileSystemException) Expect.fail("Not expected error: $err");
     completer.complete("file test, ok.");
-    events.add("FileException");
+    events.add("FileSystemException");
   });
   return completer.future;
 }
@@ -41,10 +41,10 @@ main() {
   // hang if the callbacks are not invoked and the test will time out.
   asyncStart();
   testSocketException()
-    .then((_) => testFileException())
+    .then((_) => testFileSystemException())
     .then((_) {
       asyncEnd();
-      Expect.listEquals(["SocketException", "FileException"],
+      Expect.listEquals(["SocketException", "FileSystemException"],
                         events);
     });
 }