Use ty::TraitRef::new in rustdoc

Author: WaffleLapkin

src/librustdoc/clean/auto_trait.rs

@@ -44,7 +44,7 @@ where
         discard_positive_impl: bool,
     ) -> Option<Item> {
         let tcx = self.cx.tcx;
-        let trait_ref = ty::Binder::dummy(tcx.mk_trait_ref(trait_def_id, [ty]));
+        let trait_ref = ty::Binder::dummy(ty::TraitRef::new(tcx, trait_def_id, [ty]));
         if !self.cx.generated_synthetics.insert((ty, trait_def_id)) {
             debug!("get_auto_trait_impl_for({:?}): already generated, aborting", trait_ref);
             return None;