I wouldn't quite say that's an RFC, it's just an issue in the RFCs repo. Typically people use the issue tracker in order to represent RFCs that they would like to see written, sort of a wishlist.
Ah I misunderstood! Thinking about it a bit more and given how heavily rust uses generics it seems like having an ABI that is at all usable by another higher level language might be challenging. I guess there is always compiler plugins though :)
