Remove old InputStream and OutputStream classes from dart:io.

sdk/lib/_internal/compiler/implementation/lib/io_patch.dart

Index: sdk/lib/_internal/compiler/implementation/lib/io_patch.dart
diff --git a/sdk/lib/_internal/compiler/implementation/lib/io_patch.dart b/sdk/lib/_internal/compiler/implementation/lib/io_patch.dart
index 9ed26105e5259ca255550ee541b92c98bbf9441e..00ed80040ee15a51ab317cc7c420077879d692d6 100644
--- a/sdk/lib/_internal/compiler/implementation/lib/io_patch.dart
+++ b/sdk/lib/_internal/compiler/implementation/lib/io_patch.dart
@@ -213,10 +213,10 @@ patch class _SecureFilter {
 }
 
 patch class _StdIOUtils {
-  patch static InputStream _getStdioInputStream() {
+  patch static Stream<List<int>> _getStdioInputStream() {
     throw new UnsupportedError("StdIOUtils._getStdioInputStream");
   }
-  patch static OutputStream _getStdioOutputStream(int fd) {
+  patch static IOSink _getStdioOutputStream(int fd) {
     throw new UnsupportedError("StdIOUtils._getStdioOutputStream");
   }
   patch static int _socketType(nativeSocket) {