Clean fix for #96223
Okay, so here we are (hopefully) 👍Closes#96223
Thanks a lot to `@jackh726` for your help and explanation 🙏
- Modified `InferCtxt::mk_trait_obligation_with_new_self_ty` to take as argument a `Binder<(TraitPredicate, Ty)>` instead of a `Binder<TraitPredicate>` and a separate `Ty` with no bound vars.
- Modified all call places to avoid calling `Binder::no_bounds_var` or `Binder::skip_binder` when it is not safe.
r? `@jackh726`