`empty_line_after_outer_attribute` produced a false positive warning when
deriving `Copy` and/or `Clone` for an item.
It looks like the second point in [this comment][that_comment] is related,
as the attribute that causes the false positive has a path of
`rustc_copy_clone_marker`.
Fixes#2475
[that_comment]: https://github.com/rust-lang/rust/issues/35900#issuecomment-245978831