An import that should be resolvable is left unresolved.

Example:

``` rust
pub mod foo {
    pub mod bar {
        pub fn f() {}
    }
}

mod baz {
    pub use foo;
    pub use self::foo::bar; // This import is unresolved, but it should resolve to ::foo::bar

    pub use self::bar::f as foo;
}
```

This compiles if `foo` is copied into `baz` instead of being imported with `pub use foo;`.
