name async generators something more human friendly in type error diagnostics

compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs

@@ -1366,8 +1366,8 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
                     Some(t) => Some(t),
                     None => {
                         let ty = parent_trait_ref.skip_binder().self_ty();
-                        let span =
-                            TyCategory::from_ty(ty).map(|(_, def_id)| self.tcx.def_span(def_id));
+                        let span = TyCategory::from_ty(self.tcx, ty)
+                            .map(|(_, def_id)| self.tcx.def_span(def_id));
                         Some((ty.to_string(), span))
                     }
                 }