Prevent crashes using $arg0

[Eli Zaretskii]

> Date: Mon, 20 Feb 2006 11:04:28 -0500
> From: Daniel Jacobowitz <drow@false.org>
> Cc: gdb-patches@sourceware.org
> 
> Good idea.
> 
> > [Time passes...] Actually, I'm quite sure we should behave like I
> > suggested, since we already do that without the if clause:
> > 
> >     (gdb) print $arg0
> >     $1 = void
> >     (gdb)
> 
> And let's test that too.
> 
> Does this look better?

Yes, thanks.