Auto merge of #115221 - compiler-errors:walk-path, r=estebank

Walk through full path in `point_at_path_if_possible`

We already had sufficient information to point at the `[u8]` in `Option::<[u8]>::None` (the `fallback_param_to_point_at` parameter), we just were neither using it nor walking through hir paths sufficiently to encounter it.

This should alleviate the need to add additional logic to extract params in a somewhat arbitrary manner of looking at the grandparent def path: https://github.com/rust-lang/rust/pull/115219#discussion_r1305946358

r? `@estebank`