Auto merge of #100251 - compiler-errors:tuple-trait-2, r=jackh726

Implement `std::marker::Tuple`

Split out from #99943 (https://github.com/rust-lang/rust/pull/99943#pullrequestreview-1064459183).

Implements part of rust-lang/compiler-team#537
r? `@jackh726`

compiler/rustc_trait_selection/src/traits/select/confirmation.rs

@@ -126,6 +126,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 let data = self.confirm_const_destruct_candidate(obligation, def_id)?;
                 ImplSource::ConstDestruct(data)
             }
+
+            TupleCandidate => ImplSource::Tuple,
         };
 
         if !obligation.predicate.is_const_if_const() {