No. Apple stans, food for thought.
I would hope there will be something soon although it's Apple so not much.
Edit: Still basically no, but https://github.com/geohot/tinygrad/tree/master/ane has got the instruction format apparently.
You can attack an instruction set blind (https://recon.cx/2012/schedule/events/236.en.html).
More edit: Bingo, patent: https://patents.google.com/patent/US20190340491A1/en?oq=2019...