Use the actual frame for printing single values from the cli debugger.

tests/debugger/internal_scope_test.dart

 // Copyright (c) 2016, the Dartino 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.md file.
 
 // DartinoDebuggerCommands=b main,r,n
 // Enable view of internal frames.
 // DartinoDebuggerCommands=toggle internal
 // Step into an internal function (Random.nextInt)
 // DartinoDebuggerCommands=s,s,s
 // DartinoDebuggerCommands=bt,p
 // Disable view of internal frames.
 // DartinoDebuggerCommands=toggle internal
 // Now we should get the stack view of the top current non-internal frame(main).
-// DartinoDebuggerCommands=bt,p
+// DartinoDebuggerCommands=bt,p,p rnd
 // DartinoDebuggerCommands=q
 
 import 'dart:math';
 
 main() {
   var rnd = new Random();
   rnd.nextInt(255);
 }