Add Stdio.readByteSync and Stdio.readLineSync.

tests/standalone/io/stdin_sync_script.dart

Index: tests/standalone/io/stdin_sync_script.dart
diff --git a/tests/standalone/io/stdin_sync_script.dart b/tests/standalone/io/stdin_sync_script.dart
new file mode 100644
index 0000000000000000000000000000000000000000..20da9967d66bbbc87f5659ec049eef2a5745dafe
--- /dev/null
+++ b/tests/standalone/io/stdin_sync_script.dart
@@ -0,0 +1,18 @@
+// 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.
+
+import "dart:io";
+import "dart:json";
+
+void main() {
+  var arguments = new Options().arguments;
+  int i = 0;
+  String line;
+  while ((line = stdin.readLineSync()) != null) {
+    if (parse(arguments[i]) != line) throw "bad line at $i: ${line.codeUnits}";
+    i++;
+  }
+  if (i != arguments.length) throw "expect ${arguments.length} lines";
+  print('true');
+}