Test support for reading bitmap from parallels image format.
parallels-with-bitmap.bz2 is generated on Virtuozzo by
parallels-with-bitmap.sh

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210224104707.88430-7-vsementsov@virtuozzo.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>