`#[register_attr]` was [removed from rustc in 2022](https://github.com/rust-lang/rust/pull/101123) following decisions in [the tracking issue](https://github.com/rust-lang/rust/issues/66080) https://github.com/rust-lang/rust-analyzer/blob/db7b3b1b917992dfca74c21b835bf380b7d0f80e/crates/hir-def/src/nameres.rs#L196 Should this code path and field etc just be deleted in r-a?