Invalid never constructed warning from DeadCode scan

I tried this code:

extern "C" {
    fn printf(s: *const i8, ...);
}

trait A {
    fn a() -> i32 {
        123
    }
}

trait B: A {
    fn b() -> i32 {
        <T as A>::a() + 456
    }
}

struct T;
impl A for T {
    fn a() -> i32 {
        321
    }
}

struct S;
impl A for S {}
impl B for S {}

pub fn main() {
    let aa = S::a();
    let bb = S::b();

    unsafe {
        let a = "%i, %i\n\0";
        let b = a as *const str;
        let c = b as *const i8;

        printf(c, aa, bb);
    };
}

I expected to see this happen:

I expect no warning to occur on this code see: https://godbolt.org/z/3Ex35d13s

Instead, this happened:

test.rs:18:1: warning: struct is never constructed: ‘T’
   18 | struct T;
      | ^

This is occurring as the dead-code scan does not account for QualifiedPaths

Meta

• What version of Rust GCC were you using, git sha if possible. a1c87bfea6c5e2fd6b2d23b12b563fcaf5ec09a1

Start by reproducing the provided Rust snippet and inspect the dead-code scan's handling of QualifiedPaths. Confirm that the scan incorrectly reports struct T as never constructed; done means the warning is no longer emitted for this example.