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]