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

[Eli Zaretskii]

> From: Andrea Corallo <akrl@sdf.org>
> Cc: arash@gnu.org, larsi@gnus.org, 53497@debbugs.gnu.org
> Date: Thu, 27 Jan 2022 10:57:19 +0000
> 
> I pushed d0aac84b2a as it seems to work for me here.

Thanks.  But is it right to set comp--loadable regardless of whether
native-comp-available-p returns non-nil?