[aflag]

Yes, I meant referenced in the code, not necessarily called during execution. It makes sense to do it in the beginning if delay is referenced. I guess it was just a small optimization that they decided to do without then.

[bonzini]

The loop was in the initialization code of the unit, and the initialization code was monolithic and triggered simply by the "uses crt" statement.

[ksherlock]

Nowadays with modern linkers, your delay function could have a strong reference to a delay init constructor which would get dragged in, as needed, and run at program start up time.