ppx_tyre 0.4.3 on opam: version incompatible with OCaml 4.14

[kwshi]

The current version of ppx_tyre listed on opam is 0.4.3. On my system, which currently has OCaml 4.14 installed, installing ppx_tyre forces an OCaml compiler downgrade to 4.12 (and consequently wipe/reinstalls of everything else). This is rather annoying and basically prevents me from being able to use ppx_tyre without breaking many of the other libraries I have installed (which depend on later versions of OCaml).

I presume this is happening because of the current (listed) dependency on ocaml-migrate-parsetree<2.0.0 (which then resolves to ocaml-migrate-parsetree@1.8.0, which imposes the compiler version constraint ocaml<4.13).

Perhaps releasing/publishing a newer version (0.5.1 does it, I would guess?) to opam should resolve this issue?

[paurkedal]

ppx_tyre probably needs to be converted to use ppxlib, or at least that was the solution I did for ppx_regexp.

@Drup Do you have time to look into it?