In patterns, ellipsis should always fill in each remaining argument as
an implicit argument, even if it is an optparam or autoparam. This
prevents examples such as the one in #4555 from failing:
```lean
match e with
| .internal .. => sorry
| .error .. => sorry
```
The `internal` constructor has an optparam (`| internal (id :
InternalExceptionId) (extra : KVMap := {})`).
We may consider having ellipsis suppress optparams and autoparams in
general. We avoid doing so for now since it's possible to opt-out of
them individually (for example with `.internal (extra := _) ..`) but
it's not possible to opt-in, and it is plausible that `..` with
optparams is useful in contexts such as the `refine` tactic. With
patterns however, it is hard to imagine a use case that offsets the
inconvenience of optparams being eagerly supplied.
Closes#4555
