bug#23369: 25.0.93; CANNOT_DUMP build fails if resizing terminal during startup in tty mode

[Eli Zaretskii]

> From: Glenn Morris <rgm@gnu.org>
> Cc: Fredrik Fornwall <fredrik@fornwall.net>,  23369@debbugs.gnu.org
> Date: Tue, 26 Apr 2016 20:53:28 -0400
> 
> I found this easy to reproduce but hard to debug, but it seems like
> making window.el's internal--before-save-selected-window check
> (featurep 'frame) before it tries to call frames-on-display-list
> fixes it for me.

Thanks.

Fredrik, does this patch solve the problems you see?  If so, I think
we should install it on the emacs-25 branch.

> (Prescient comment in http://debbugs.gnu.org/22975#73 ?)

I disagree with the conclusion there.  I think what we need is to
detect all the cases like this one and fix them one by one.  Bitrot in
areas and use cases that are rarely used is nothing new in Emacs, so
this stuff will happen from time to time, there's no way around that.
But these cases cannot be too many in this case, since not much can be
going on while 'loadup' runs anyway.  We just found one more, possibly
the last, of those dark corners.