[LesterEvSe]

Adds Bitcoin jets in preparation for Bitcoin support in SimplicityHL #436, since rust-simplicity already provides all of them

Checklist

• If this PR adds or changes a language feature, it is used in
  examples/kitchen_sink.simf, and test-data/kitchen_sink.json is
  regenerated.

[KyrylR]

ACK e2cd9b1; successfully ran local tests

Not sure about putting it under the feature flag, but it is nice to be careful in the beginning

Anyway we can lift it easily later on

Overall the set of jets is unlikely to change, so LGTM

[ivanlele]

I think I saw something similar in @delta1 branch somewhere, just a note to not do the double work.

[LesterEvSe]

I don't think it's double work: this PR upstreams that work, since @delta1 hasn't opened a PR for it. I took the jets from the PoC branch, which adapted them from delta1's bitcoin branch as I understand it

[stringhandler]

I have already tested bitcoin support using @delta1's branch, so I'd need to re-evaluate each of them. Currently I'm in favour of @delta1's, since I've seen it working, but I still need to review it. Is it possible to merge the two branches together so that they can be reviewed as one.

One thing I'm not keen on, more so in #436 than here, is the -Z flag for bitcoin. I don't see the need for this, since users targeting bitcoin will know it's unstable and a --target option seems sufficient and means we don't need to undo the changes in future.

[stringhandler]

utACK ae6d9bb

[stringhandler]

ACK ae6d9bb; Ran tests, fuzz locally