Fix explicit_predicates_of

src/librustc_typeck/collect.rs

@@ -1920,12 +1920,7 @@ fn explicit_predicates_of<'a, 'tcx>(
 
     let hir_id = match tcx.hir().as_local_hir_id(def_id) {
         Some(hir_id) => hir_id,
-        None => {
-            return Lrc::new(ty::GenericPredicates {
-                parent: None,
-                predicates: Vec::new(),
-            })
-        }
+        None => return tcx.predicates_of(def_id),
     };
     let node = tcx.hir().get_by_hir_id(hir_id);