Query user with gdb MI intepreter

[Denis PILAT]

Nick Roberts wrote:
>  > If actual behavior is not correct, then I will propose a simple patch 
>  > that is already in place in my version of gdb sources.
>
> I don't think anyone has considered how MI should behave after an internal
> error which really means there is a bug in GDB anyway. 
There is, but I don't have any patch to submit about it, sorry.
dwarf2_restore_rule() is called from execute_cfa_program() with 
fs->initial.reg set to 0 which leads to a gdb_assert().
That, for sure, comes from a problem we have in our in-house compiler 
that do not generate right debug information.