Fix minor bug, avoid douple unpacking in the case of    (module M:S) | (module M:S) -> ... M .. That is or pattern whose arguments contain module variables (AST: Ppat_unpack).
Fix minor bug, avoid douple unpacking in the case of
   (module M:S) | (module M:S) -> ... M ..
That is or pattern whose arguments contain module variables
(AST: Ppat_unpack).

gerdstolpmann/ocaml,yunxing/ocaml,msprotz/ocaml,msprotz/ocaml,eliberis/ocaml,gerdstolpmann/ocaml,eliberis/ocaml,yunxing/ocaml,yunxing/ocaml,msprotz/ocaml,yunxing/ocaml,eliberis/ocaml,gerdstolpmann/ocaml,eliberis/ocaml,msprotz/ocaml,gerdstolpmann/ocaml,eliberis/ocaml,yunxing/ocaml,gerdstolpmann/ocaml,msprotz/ocaml