bug#61960: 30.0.50; Unexec build reliably crashes during loadup

[Andrea Corallo <akrl@sdf.org>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Andrea Corallo <akrl@sdf.org>
>> Cc: 61960@debbugs.gnu.org, Konstantin Kharlamov <hi-angel@yandex.ru>
>> Date: Mon, 06 Mar 2023 17:12:55 +0000
>> 
>> > debugging session :) Yeah, if native compilation isn't supposed to work with
>> > unexec(), it might be a good idea to disable that, sure.
>> 
>> Eli related to this, do you think is better to install the attached on
>> 29 or master?
>
> Don't we already have an equivalent test?
>
>   if test "${with_native_compilation}" != "no"; then
>       if test "${HAVE_PDUMPER}" = no; then
> 	 AC_MSG_ERROR(['--with-native-compilation' requires '--with-dumping=pdumper'])
>       fi

So IIUC we can compile emacs with both unexec and pdumper support, they
are not mutually exclusive, and we can specify which one to use for the
first dump with --with-dumping.

So yeah I think we have to prevent native compilation to be compiled
with unexec support, even if it's not the way Emacs is dumped the first
time.

  Andrea