Rollup merge of #109506 - BoxyUwU:debugable_bound_var_printing, r=compiler-errors

make param bound vars visibly bound vars with -Zverbose

I was trying to debug some type/const bound var stuff and it was shockingly tricky due to the fact that even with `-Zverbose` enabled the `T` in `for<T> T: Trait` prints as `T` making it seem like its `TyKind::Param` when it is infact `TyKind::Bound`. This PR "fixes" this when `-Zverbose` is set to allow rendering it as `^T` or `^1_T` depending on binder depth.

r? ```@compiler-errors```

Author: matthiaskrgr