The compatible architectures are not symmetric: x86_64 and aarch64 can
run i386 and arm binaries, but i386 and arm cannot usually run x86_64
and aarch64 binaries.
This caused test failures on Debian i386 autobuilders.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Closes: #2603
Approved by: matthiasclasen