Some more boilerplate could be removed by moving some CIL-specific implementations that only compare IDs into Deriving.Cil. Right now their comparisons are duplicated all over the place.

It kind of annoys me how such comparisons are spread around. For example .vid\s+= yields 39 different places where varinfos are checked for equality. It would actually be better organized if all of those just delegated to Basetype.Variables.equal. Similarly with all the other modules we have for CIL types in Basetype (which might be better called CilType or something).

Then one doesn't need to define Deriving.Cil.equal_varinfo etc and make sure Deriving.Cil is opened everywhere. In fact, it could even make Deriving.Cil completely redundant because as seen in #210, we don't actually want the derived to_yojson functions anyway.

I'll pursue this line of refactoring in a separate branch and PR. I think it's reasonable to have common and well-behaved implementations for most Printable functions for these CIL types in a clear place.

These and some other such places seem problematic in light of

 If an ord comparator returns a value outside -1..1 range, the behavior is unspecified.

from https://github.com/ocaml-ppx/ppx_deriving#plugins-eq-and-ord

One should probably patch all such places to return values from [-1,1]?

One should probably patch all such places to return values from [-1,1]?

I noticed that at some point too, but chose to ignore it, because it worked regardless. And ppx_deriving_ord actually nowhere makes any assumptions about the range, so I don't think it's an issue. But I'll go ahead and wrap those with Stdlib.compare anyway, so this doesn't stay open ended.