Unstable formatting of comments

[cknitt]

Example adapted from jscomp/test/tramp_fib.res:

let rec fib = (n, k) =>
  switch n {
  | 0 | 1 => k(1)
  | _ =>
    Suspend(
      () =>
        fib(n - 1, (v0) =>
          fib(n - 2, (v1) =>
            k(v0 + v1)
            /* comment */
          )
        ),
    )
  }

Formatted:

let rec fib = (n, k) =>
  switch n {
  | 0 | 1 => k(1)
  | _ =>
    Suspend(
      () =>
        fib(n - 1, v0 =>
          fib(n - 2, v1 => k(v0 + v1))
/* comment */
        ),
    )
  }

Formatted again:

let rec fib = (n, k) =>
  switch n {
  | 0 | 1 => k(1)
  | _ =>
    Suspend(
      () =>
        fib(n - 1, v0 => fib(n - 2, v1 => k(v0 + v1))),
/* comment */
    )
  }

Formatted once more:

let rec fib = (n, k) =>
  switch n {
  | 0 | 1 => k(1)
  | _ =>
    Suspend(
      () =>
        fib(n - 1, v0 => fib(n - 2, v1 => k(v0 + v1))),
        /* comment */
    )
  }

After the third formatting, the output is now stable.