Use is_lang_item more

compiler/rustc_trait_selection/src/traits/query/type_op/prove_predicate.rs

@@ -1,3 +1,4 @@
+use rustc_hir::LangItem;
 use rustc_infer::traits::Obligation;
 pub use rustc_middle::traits::query::type_op::ProvePredicate;
 use rustc_middle::traits::query::NoSolution;
@@ -20,8 +21,7 @@ impl<'tcx> super::QueryTypeOp<'tcx> for ProvePredicate<'tcx> {
         // such cases.
         if let ty::PredicateKind::Clause(ty::ClauseKind::Trait(trait_ref)) =
             key.value.predicate.kind().skip_binder()
-            && let Some(sized_def_id) = tcx.lang_items().sized_trait()
-            && trait_ref.def_id() == sized_def_id
+            && tcx.is_lang_item(trait_ref.def_id(), LangItem::Sized)
             && trait_ref.self_ty().is_trivially_sized(tcx)
         {
             return Some(());