35dbc5ec47
Replace the `&'tcx List<Ty<'tcx>>` in `TyKind::Tuple` with `SubstsRef<'tcx>` Part of the suggested refactoring for https://github.com/rust-lang/rust/issues/42340. As expected, this is a little messy, because there are many places that the components of tuples are expected to be types, rather than arbitrary kinds. However, it should open up the way for a refactoring of `TyS` itself. r? @nikomatsakis