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

[Eli Zaretskii]

> From: Jimmy Yuen Ho Wong <wyuenho@gmail.com>
> Date: Fri, 5 Jan 2018 17:42:49 +0000
> Cc: 29972@debbugs.gnu.org
> 
> The fundamental reason appears to be desktop.el needs an efficient and 
> reliable way to know what buffer
> local variables are minor modes, since `minor-mode-list` is just a global 
> list of loaded minor-modes,
> `minor-mode-alist` is as close as you get.

So maybe desktop.el should have defcustom with the list of minor
modes, whose default value is computed from minor-mode-alist, but
which users could customize to add any additional minor modes?