create a s390x github action

[skoudoro]

          I don't know how to bind the below on Github Actions, but maybe this will give you ideas.

To test on big endian, my go to platform is to use qemu-system-s390x coupled to binfmt kernel settings, provided by Debian packages qemu-system-misc and qemu-user-static. Once installed, I can spawn a Debian s390x system root tree with e.g.:

# debootstrap --arch s390x sid /srv/chroot/sid-390x http://ftp.fr.debian.org/debian

Once done, I can chroot straight into the tree and, thanks to binfmt, qemu-system-s390x will "interpret" the s390x executables:

# uname -m
x86_64
# chroot /srv/chroot/sid-390x
# uname -m
s390x

Crude yet effective. Main drawback is, that emulation for s390x is slow: running the test suite took some eight hours to run on my machine, to compare to one quarter of hour on the native cpu.

I'm using actually a configuration a bit more elaborate, but you get the idea.

Originally posted by @emollier in #3043 (comment)

[DanonymousCoder]

Hi @skoudoro I would love to work on this issue

[skoudoro]

You can go ahead @DanonymousCoder. Thanks !

[viusic]

Hi @skoudoro, are there any specific requirements and testing needs?