* 8.20: [Smarter guard condition](https://github.com/coq/coq/pull/17986) should allow us to define `fmap`/`mbind` instances for `list` that can be used in nested recursion and do not require the `csimpl` hack.
* 8.20 [prim proj in ssrrewrite](https://github.com/coq/coq/pull/19213)
* 8.20 [list naming](https://github.com/coq/coq/pull/18564) Remove compatibility copies of lemmas in std++