Fix a wrongly moved variable declaration.

types/types.ml

@@ -3,6 +3,8 @@ let std_compare = compare
 open Ident
 module U = Encodings.Utf8
 
+let count = ref 0
+
 let () =
   Stats.register Stats.Summary (fun ppf ->
       Format.fprintf ppf "Allocated type nodes:%i@\n" !count)
@@ -287,7 +289,6 @@ type descr = Descr.t
 type node = Node.t
 
 let forward_print = ref (fun _ _ -> assert false)
-let count = ref ~-1
 
 let make () =
   incr count;