bug#48079: Temporary files while building after native-comp merge

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: Andrea Corallo <akrl@sdf.org>,  Eli Zaretskii <eliz@gnu.org>,
>   48079@debbugs.gnu.org
> Date: Wed, 05 May 2021 10:35:02 +0200
> 
> I guess we can't set up a signal trap to delete the temp file if we're
> being interrupted?

You mean, in the Makefile?  That won't handle the cases where the
compilation is manually invoked (e.g., from a running Emacs).