[Bug c++/17314] Error message wrongly shows declared rather than inherited access

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17314

--- Comment #18 from Jason Merrill <jason at gcc dot gnu.org> ---
(In reply to Jason Merrill from comment #17)
> It would be good to get the same diagnostic as in comment #4.

And also give a warning about the private virtual base.