bug#53497: 29.0.50; native-compile after restarting Emacs

[Eli Zaretskii]

> From: Andrea Corallo <akrl@sdf.org>
> Cc: Eli Zaretskii <eliz@gnu.org>, Arash Esbati <arash@gnu.org>,
>         53497@debbugs.gnu.org
> Date: Sat, 29 Jan 2022 07:40:37 +0000
> 
> >> I suspect this is related to the recent changes of where
> >> `native-comp-eln-load-path' is set, maybe Lars can comment.
> >
> > That's certainly possible -- it's really difficult to trace the logic
> > here in the startup code.
> 
> Yeah our startup has a lot of hidden dependecies.
> 
> > Does moving the setting earlier again fix the problem?
> 
> If you refer to bf695b937e that's not sufficient, the test was done with
> it installed.  I haven't checked if bf695b937e has restored the state of
> say one week ago (in terms of where we set native-comp-eln-load-path) or
> not.
> 
> But yeah the bottom line is that indeed we need to have
> native-comp-eln-load-path set before we expect the native compiler
> machinery to work.

I don't think we can move the initialization of
native-comp-eln-load-path to after the call to command-line, because
Lisp packages can be loaded as early as while loading early-init.el.
So we need to initialize native-comp-eln-load-path as soon as we have
user-emacs-directory, and then amend the value after calling
command-line.

I installed a fix along these lines which seems to be working for me.
Arash, please see if your problems are solved now.