Comments at end of line for polymorphic variants are duplicated on refmt.

Master branch:
```
  type widget_state = [
    | `DEFAULT /* here */
    | `HOVER
    | `ACTIVE
  ];
```

`refmt` leaves:

```
  type widget_state = [
    | `DEFAULT /* here */
    | `HOVER  /* here */
    | `ACTIVE  /* here */
  ];
```

And it causes the duplication to grow each refmt.