Various changes to compile new files in coq
Reopening of !245 (merged)
We make various changes to compile new files in Coq with coq-of-ocaml. In particular, we:
- add some axiom annotations for functions using GADTs;
- remove the mutual dependency of definitions which are not actual mutual;
- annotate some function types so that they are not polymorphic where it is not expected.
Part of a larger goal to compile the protocol in Coq.