Improve name resolution failure detection

[jseyfried]

Right now, this compiles ...

pub type T = ();

mod foo {
    pub use super::T;
}

mod bar {
    pub use super::*; // ... but replacing `*` with `T` causes unresolved imports.
}

pub use foo::*;
pub use bar::*;

Neither case compiled before #31726, when even this would not compile:

pub type T = ();
mod foo {
    pub use super::T;
}

pub use foo::*;

[jseyfried]

This a violation of the first coherence condition from this comment.