8221: Prefer adding `mod` declaration to lib.rs over file.rs in UnlinkedFile fix r=Veykril a=Veykril
When there is a `lib.rs` and `main.rs` in one crate, one usually wants the `lib.rs` file to declare the modules.
bors r+
Co-authored-by: Lukas Wirth <lukastw97@gmail.com>
ce6bb5ccca