bug#29972: 25.3; dired-hide-details-mode does not persist in desktop session

[Eli Zaretskii]

> From: Noam Postavsky <npostavs@users.sourceforge.net>
> Date: Fri, 5 Jan 2018 13:29:49 -0500
> Cc: Jimmy Yuen Ho Wong <wyuenho@gmail.com>, 29972@debbugs.gnu.org
> 
> Would it help if define-minor-mode recorded what the
> variable/expression is (e.g., by putting a property on the function
> symbol)?

Not sure what should desktop.el do with that.  Loop on all symbols in
obarray looking for those with that property?