Compile `block_header_repr.ml` and `michelson_v1_primitives.ml` in Coq
requested to merge guillaume-claret@block_header_repr-and-michelson_v1_primitives-for-coq into proto-proposal
Reopening of !240 (merged)
Small changes to two files which so that they compile in Coq:
- break mutual dependency between types which actually are not mutually dependent;
- add
@coq_axiom
to ignore some failing functions (the current fix would incur a performance cost).
Part of a larger goal to compile the protocol in Coq as it is (nomadic-labs/tezos#161).