bug#12463: 24.2; pos-visible-in-window-p gets slower over time

[Eli Zaretskii]

> From: Chong Yidong <cyd@gnu.org>
> Cc: lekktu@gmail.com,  jwalt@garni.ch,  12463@debbugs.gnu.org
> Date: Sat, 22 Sep 2012 22:14:47 +0800
> 
> I've committed the patch to trunk.

Thanks.

> Please let me know if this causes any problems on Windows.

None that I could spot.

> I left the LIBRARIES issue alone in this patch, but I do think we should
> eliminate the second arg to init-image-library.  I don't see what value
> other than `dynamic-library-alist' could possibly be supplied for this
> argument.  Any objections to that?

Not from me.