bug#39373: 27.0.50; [PATCH] mode-local-print-bindings broken with lexical-binding

[Eli Zaretskii]

> From: Mattias Engdegård <mattiase@acm.org>
> Date: Sat, 1 Feb 2020 20:24:56 +0100
> Cc: 39373@debbugs.gnu.org
> 
> It all seems rather fragile to me, and I'd rather add a note about not using 
> add-to-list for lexical variables to its doc string and the manual, and fix 
> all the calls listed above.

I tend to agree.  Stefan, any comments?

> Two patches attached: a doc update, and a replacement of add-to-list in the 
> cases listed above.

LGTM, on both counts, but let's hear from Stefan (and others, if
someone has an opinion).

Thanks.