Re: master 19a3b499f84: ; * lisp/loadup.el: Don't prohibit advice when ls-lisp is loaded.

[Stefan Monnier <monnier@iro.umontreal.ca>]

> +(unless (featurep 'ls-lisp)
> +  ;; Actively disallow advised functions during preload since:
> +  ;; - advices in Emacs's core are generally considered bad style;
> +  ;; - `Snarf-documentation' looses docstrings of primitives advised
> +  ;;   during preload (bug#66032#20).
> +  ;;
> +  ;; Don't verify this under MS-Windows and Android, both systems that
> +  ;; load ls-lisp, which advises insert-directory.

How 'bout we fix this as well?

IOW, merge `insert-directory` and `ls-lisp--insert-directory`
by allowing `insert-directory-program` to be nil
(as a replacement for the `ls-lisp-use-insert-directory-program`
boolean) in which case we use the ls-lisp code?


        Stefan