ref: b037d54f64917b1df175f33226ef21f20f94b0f7
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)!