GitLab

thanks to Johanness Kanig for the bug report and analysis

introduced new transformation eliminate_non_struct_recursion for that purpose
uses Decl.check_termination tomake the check and the pretty-print
(could probably be improved to avoid 3 calls to check_termination)

to be proved with Coq, later
to do that, it would be nice to have recursive definitions translated to Coq
as such when possible