Camelid 8c43160744 driver: Use atty instead of rolling our own
Rationale:

- `atty` is widely used in the Rust ecosystem
- We already use it (in `rustc_errors` and other places)
- We shouldn't be rolling our own TTY detector when there's a
  widely-used, well-tested package that we can use
2021-01-11 19:59:25 -08:00
..