Fix argument order of clone() for s390x in seccomp filter
Marked as WIP for now because it's probably better to wait for the Flatpak change to be merged before accepting this copy. (Now merged)
From Julian Andres Klode, via https://github.com/flatpak/flatpak/pull/3777
clone() is a mad syscall with about 4 different argument orders. While most of them agree that argument 0 is flags, s390 and s390x have the flags argument second - A0 is the child stack pointer there.
[smcv: Add an explanatory comment; also test
__CRIS__, for completeness;
apply change from Flatpak to the copy of this code in gnome-desktop]