Sorry, I meant that `unf` could be included as a hard dependency since `unicode` was a hard dependency before. `unf` doesn't require any C extensions, which is why it works in JRuby.

We're using `fog` via `carrierwave` to generate S3 urls. This happens hundreds of times per request in the worst case. So if `#constant_missing` is slow, it could conceivably make a noticeable difference. I'll take another look at our profiling results to make sure.