Rollup merge of rust-lang#56466 - ljedrz:delete_tuple_slice, r=nikomatsakis

data_structures: remove tuple_slice

It looks like we're not using it anywhere.

Author: GuillaumeGomez

src/librustc_data_structures/lib.rs

@@ -81,7 +81,6 @@ pub mod sync;
 pub mod tiny_list;
 pub mod thin_vec;
 pub mod transitive_relation;
-pub mod tuple_slice;
 pub use ena::unify;
 pub mod vec_linked_list;
 pub mod work_queue;