[RFA] Ignore data minimal symbols for breakpoint linespecs

[Joel Brobecker]

> gdb/ChangeLog:
> 
>         * linespec.c (struct collect_minsyms) [list_mode]: New field.
>         (add_minsym): Ignore data symbols if not in list mode.
>         (search_minsyms_for_name): Set local.list_mode.
> 
> gdb/testsuite/ChangeLog:
> 
>         * gdb.base/dmsym.c, gdb.base/dmsym_main.c, gdb.base/dmsym.exp:
>         New files.

I would normally wait to give the original author (Tom in this case)
some time to comment, but given that it fixes a couple of regressions
as well, and the fact that Jan is OK, I went ahead and checked it in.
If Tom has some comments, I don't mind fixing or reverting at all.

This is HEAD only. I think we'll want that for the branch, but I'll
wait for Tom's feedback, if any.

-- 
Joel