Delegation: fix ICE on `bound_vars` divergence Fixes https://github.com/rust-lang/rust/issues/122550. Bug was caused by divergence between lowered type and corresponding `bound_vars` in `late_bound_vars_map`. In this patch `bound_vars` calculation for delegation item is moved from `lower_fn_ty` to `resolve_bound_vars` query. r? `@petrochenkov`