Stop using ty::GenericPredicates for non-predicates_of queries

compiler/rustc_lint/src/multiple_supertrait_upcastable.rs

@@ -45,8 +45,7 @@ impl<'tcx> LateLintPass<'tcx> for MultipleSupertraitUpcastable {
             let direct_super_traits_iter = cx
                 .tcx
                 .explicit_super_predicates_of(def_id)
-                .predicates
-                .into_iter()
+                .iter_identity_copied()
                 .filter_map(|(pred, _)| pred.as_trait_clause());
             if direct_super_traits_iter.count() > 1 {
                 cx.emit_span_lint(