A macro call records a handful of forms, not sixty-four

lib/expand.ml

@@ -187,7 +187,7 @@ let call ~loc (fn : Dynload.addr) (args : Form.t list) : Form.t =
      [Macro] and on the way out of one — so no address recorded here can be
      handed to a second allocation while the table still holds it, and the
      table is dropped the moment this returns either way. *)
-  let sites : sites = Hashtbl.create 64 in
+  let sites : sites = Hashtbl.create 8 in
   let a = Dynload.take (max (n * form_size) 1) in
   List.iteri
     (fun i x -> write sites (Nativeint.add a (Nativeint.of_int (i * form_size))) x)