Duplicate path resolution errors in `resolve`

[jseyfried]

For example,

mod foo {}

use foo::bar::baz::{}; // This emits 2 errors
fn main() {
    foo::bar::baz(); // This emits 2 errors
    <() as foo::bar>::baz(); // This emits 3 errors
    foo::bar::baz { x: 0 } // This emits 2 errors
}

[Aatch]

Looks like the errors aren't true duplicates, instead it first complains about not finding bar in foo, then complains about not being able to resolve foo::bar::baz.

The general pattern is where B fails because A fails and B depends on A, we should probably be detecting these cases and silencing the dependent errors.

[jseyfried]

Indeed -- I should have been more specific.