bug#30182: Update

[Eli Zaretskii]

> Date: Sun, 28 Jan 2018 09:26:47 +0100
> From: martin rudalics <rudalics@gmx.at>
> CC: Eli Zaretskii <eliz@gnu.org>, 30182@debbugs.gnu.org
> 
> Thanks for checking and for reporting this bug in the first place.  It
> revealed an awfully silly, costly and completely unnecessary way of
> implementing the desired behavior.

Btw, if using window-at-side-p is so much more efficient than
window-in-direction, then how come the former is not documented in the
ELisp manual?  Should it be?