I can't wait until I find such a project that is in a usable state! I've tried all of these (save dagger, no releases yet) and always hit some issue due to their immaturity.
I think the most stable implementation in this space (if limited in scope) would be Apple's Rosetta. Sadly both closed-source and now abandoned; if it was opened up, it'd be great to base a more general A-to-B translator on.
https://github.com/libcpu/libcpu
http://dagger.repzret.org/
https://github.com/draperlaboratory/fracture