Fix pressing down in the TUI (Re: [RFC 8.3 0/3] Some style fixes)

[Tom Tromey]

>>>>> "Simon" == Simon Marchi <simark@simark.ca> writes:

Simon> The obvious patch would be to fetch fullname again after calling open_source_file,
Simon> like so:

I think this is fine, especially with a comment explaining it.

Simon> ... but maybe there's a better way?  Should we instead create a
Simon> local copy of FULLNAME?

Ideally we'd rewrite this whole area.  I don't much like stashing the
full name in the symtab, and also it seems to me that gdb calls open,
etc, far too much.

Tom