ppx_optcomp_light improvements

[vouillon]

No description provided.

[hhugo]

What about matching on signature instead of individual items ? Similar to what we do for structures?

[vouillon]

OxCaml defines signatures using a record:

and signature =
  {
    psg_modalities : modalities;
    psg_items : signature_item list;
    psg_loc : Location.t;
  }

while mainstream OCaml uses a plain list:

and signature = signature_item list

I did not see any other way to write some code compatible with both.

[hhugo]

This is unfortunate. Do we really need conditional sig item ? Can you point me to the use cases ?