[sledge] Remove dead List.remove

Reviewed By: jvillard

Differential Revision: D18736377

fbshipit-source-id: 49626e7c6

sledge/src/import/import.ml

@@ -212,8 +212,6 @@ module List = struct
     in
     remove_ [] xs
 
-  let remove xs x = try Some (remove_exn xs x) with Caml.Not_found -> None
-
   let rec rev_init n ~f =
     if n = 0 then []
     else

sledge/src/import/import.mli

@@ -167,7 +167,6 @@ module List : sig
       argument, or raise [Not_found] if no such element exists. [equal]
       defaults to physical equality. *)
 
-  val remove : 'a list -> 'a -> 'a list option
   val rev_init : int -> f:(int -> 'a) -> 'a list
 
   val symmetric_diff :