Hmm... nothing. I would rather not eat the last day before my death. It's not as if it's necessary for survival, it would just be a waste of perfectly good food (thus, unnecessarily killed animals, plants and/or fungi). Furthermore one's bowels sometimes become loose at the moment of death, which is not very dignified. Of course I would technically still have a last meal at some point, but not shortly before death, I would probably not know it's the last, it wouldn't have the same meaning, and I wouldn't care what it would be.
Maybe something suitable for libation, at most, but that doesn't count as a meal.