ref: f5b19906047cd318f901557731021ad136e5643f
dir: /test/asm/purge-ref.err/
error: purge-ref.asm(4): Symbol "ref" is referenced and thus cannot be purged error: purge-ref.asm(11): Symbol "NotOK" is referenced and thus cannot be purged error: purge-ref.asm(15): Symbol "EvenLessOK" is referenced and thus cannot be purged error: Assembly aborted (3 errors)!