'make check-acceptance' eats lots of disk space and never cleans it up

[Peter Maydell]

It looks like 'make check-acceptance' creates directories in
build/clang/tests/results which are huge and which it never
cleans up. For example one of my build directories (configured
just for arm targets) has over 350 'job-[timestamp]' directories,
many of which are 2.5GB or more in size.

I assume most of this is artefacts (disk images etc) needed to
rerun the tests. That's useful to keep around so you can manually
run a test. However, we should be sharing this between runs, not
creating a fresh copy for every time check-acceptance is
run, surely ?

I just freed 72 GB (!) of disk on my local box just by doing
rm -rf build/arm-clang/tests/results/ ...

thanks
-- PMM