bug#46256: [feature/native-comp] AOT eln files ignored if run from build tree

[Eli Zaretskii]

> From: Pip Cet <pipcet@gmail.com>
> Date: Fri, 5 Mar 2021 15:18:12 +0000
> Cc: Andrea Corallo <akrl@sdf.org>, 46256@debbugs.gnu.org
> 
> > Then perhaps we could invoke Emacs only in order to detect when the
> > ABI has changed.
> 
> IIUC, the ABI only changes when DEFUNs do, and then we regenerate most
> of the Emacs binaries anyway, so we could make abi-hash depend on
> gl-stamp/globals.h?

Why should we have the knowledge about what determines the ABI hash in
more than one place?

> > Because when that happens, we need to regenerate all
> > the preloaded *.eln files anyway, so there's no need to test
> > individual files.  Right?
> 
> But do we want to keep the old files around in case the ABI changes
> back? I don't think we do.

That's a separate issue.  It depends on whether the build included
non-preloaded files.