dataConArgRep _ _ arg_ty (HsUnpack Nothing)
  | (rep_tys, wrappers) <- dataConArgUnpack arg_ty
  = (HsUnpack Nothing, rep_tys, wrappers)
dataConArgRep _ _ arg_ty (HsUnpack Nothing)
  | (rep_tys, wrappers) <- dataConArgUnpack arg_ty
  = (HsUnpack Nothing, rep_tys, wrappers)
dataConArgRep _ _ arg_ty (HsUnpack Nothing)
  | (rep_tys, wrappers) <- dataConArgUnpack arg_ty
  = (HsUnpack Nothing, rep_tys, wrappers)