On nightly, the following code triggers dead_code even though it should not.

#![feature(inherent_associated_types)]
#![allow(incomplete_features)]

fn main() {
    let _: Struct::Item = ();
}

struct Struct;
impl Struct { type Item = (); }

warning: associated type `Item` is never used
 --> min.rs:9:20
  |
9 | impl Struct { type Item = (); }
  | -----------        ^^^^
  | |
  | associated type in this implementation
  |
  = note: `#[warn(dead_code)]` on by default

warning: 1 warning emitted

Actually until recently, dead_code was never triggered at all for inherent associated types.
PR #110277 was just merged which started visiting more associated items exposing this bug.
The dead_code pass never considers IATs as live symbols (live_symbols) even in cases where they should be.

This feels like a regression but technically speaking it is not:
We switched from one extreme to the other. Thus not marking as such.

@rustbot label A-lint F-inherent_associated_types requires-nightly