Module `Jane_syntax.Include_functor`

The ASTs for include functor. When we merge this upstream, we'll merge these into the existing P{sig,str}_include constructors (similar to what we did with T{sig,str}_include, but without depending on typechecking).

type signature_item =

| Ifsig_include_functor of Ppxlib_ast.Parsetree.include_description

type structure_item =

| Ifstr_include_functor of Ppxlib_ast.Parsetree.include_declaration

val sig_item_of : 
  loc:Location.t ->
  signature_item ->
  Ppxlib_ast.Parsetree.signature_item

val str_item_of : 
  loc:Location.t ->
  structure_item ->
  Ppxlib_ast.Parsetree.structure_item