Hey @WG-ffi-unwind -- I took a stab at a draft for the "initial RFC", opened in this PR.
I'm not sure @Kyle Strand if you had any in-progress work -- if so, sorry for stepping on your toes. It just seemed like there was a bit of confusion over what I had in mind so I figured i'd take a stab myself.
I'm also skimming @gnzlbg's PR -- I think a lot of this material would fit right in, and should be merged in.
Though i've far exceeded the 60 minute quota I gave myself to work on this stuff this morning :) so gonna have to stop