`use Trait::{};` acts as `use Trait;`

[petrochenkov]

mod m {
    pub trait Tr {
        fn method(&self) {}
    }
    
    impl<T> Tr for T {}
}

use m::Tr::{};

fn main() {
    // Expected behavior: error, `Tr` is not in scope.
    // Actual behavior: not an error.
    0u8.method();
}

The regression was introduced in c57f0a7 (Rust 1.31).