Bug#910542: better support for OCaml object files

[Thomas Gazagnaire]

Package: diffoscope

The OCaml compiler generates a bunch of binary files (cmi, cmi, cmt, cmti, cmx, cmxa). Currently diffoscope seems to only prints  binary diffs:

https://tests.reproducible-builds.org/archlinux/extra/ocaml-result/ocaml-result-1.3-1-x86_64.pkg.tar.xz.html

It would be nice to show more structured information instead; a subset of this information could already be dumped with `ocamlobjinfo` command which might be enough in most cases.

Thomas