Restore compat with 4.07-

Signed-off-by: Nathan Rebours <[email protected]>

src/ast_builder.mli

@@ -96,7 +96,8 @@ module type S = sig
 end
 
 (** Build Ast helpers with the location argument factorized. *)
-module Make (_ : Loc) : S
+module Make (Loc : Loc) : S
+[@@ocaml.warning "-67"]
 
 val make : Location.t -> (module S)
 (** Functional version of [Make]. *)

src/driver.mli

@@ -218,12 +218,13 @@ end
     In the future we could also use this to directly compute the dependencies
     and pass them here, to avoid calling ocamldep separately. *)
 module Create_file_property
-    (_ : sig
+    (Name : sig
       val name : string
     end)
     (T : Sexpable.S) : sig
   val set : T.t -> unit
 end
+[@@ocaml.warning "-67"]
 
 val standalone : unit -> unit
 (** Suitable for -pp and also usable as a standalone command line tool.

src/pp_ast.mli

@@ -83,7 +83,7 @@ end
 module type Configured = S with type 'a printer = 'a configured
 module type Configurable = S with type 'a printer = 'a configurable
 
-module Make (_ : Conf) : Configured
+module Make (Conf : Conf) : Configured [@@ocaml.warning "-67"]
 
 val make : Config.t -> (module Configured)