[mi] What frame should -data-list-register-values be using?

[Andrew Cagney]

> Right now, both -data-list-register-values and -data-list-changed-registers
> use deprecated_selected_frame.  This is both wrong and segfault-prone.
> The obvious thing to do would be to use get_selected_frame... but take a
> look at mi_cmd_data_write_register_values.  Completely undocumented, I might
> add.  It uses deprecated_write_register_bytes so it's actually blatting the
> _current_ frame.

I think the intent is that it update the register of the selected frame 
- Insight's register window tracks the selected frame and this would be 
trying to mimic that.

Don't forget that until very recently not even the CLI could come close 
getting this right - the required infrastructure was simply missing.  I 
suspect this is also why it wasn't documented or tested.

Andrew