Bad handling of path expression during monomoprhization

[philberty]

Summary

This bug is hidden most of the time but we get away with it in simple test cases so technically this test case "works" but only by accident.

Reproducer

I tried this code:

#[lang = "sized"]
trait Sized {}

trait Trait {
    fn do_thing();
}

struct MyType;

impl Trait for MyType {
    fn do_thing() {}
}

struct Wrapper<T: Trait> {
    value: T,
}

impl<T: Trait> Wrapper<T> {
    fn call_it() {
        T::do_thing(); // <---------- this only works by accident... 'T' isnt getting monomorphized to MyType here
    }
}

fn main() {
    let _ = Wrapper::<MyType> { value: MyType };
    Wrapper::<MyType>::call_it();
}

Does the code make use of any (1.49) nightly feature ?

• Nightly

Godbolt link

No response

Actual behavior

The current behavior is, it doesnt monomoprhize but there is only 1 impl anyway and it defaults

Expected behavior

I expected to see the type get monomorphized in the logs properly

GCC Version

110783a