Type parameters (type t) do not seem to care about multi-line

[Niols]

As of f35eee4, Topiary formats:

let foo
    (type t)
    (x : t)
    : t
  =
  result

as:

let foo (type t)
    (x : t)
    : t
  =
  result

Note how (type t) goes on the same line as the binding, which does not seem to fit the rest of Topiary's formatting. I would expect the formatting to be unchanged.

To reproduce:

$ nix run github:tweag/topiary/f35eee4 -- format -l ocaml <<EOF
let foo
    (type t)
    (x : t)
    : t
  =
  result
EOF