Allow internal untranslatable diagnostic

compiler/rustc_hir_typeck/src/callee.rs

@@ -380,6 +380,9 @@ fn confirm_builtin_call(
                 // Unit testing: function items annotated with
                 // `#[rustc_evaluate_where_clauses]` trigger special output
                 // to let us test the trait evaluation system.
+                // Untranslatable diagnostics are okay for rustc internals
+                #[allow(rustc::untranslatable_diagnostic)]
+                #[allow(rustc::diagnostic_outside_of_impl)]                
                 if self.tcx.has_attr(def_id, sym::rustc_evaluate_where_clauses) {
                     let predicates = self.tcx.predicates_of(def_id);
                     let predicates = predicates.instantiate(self.tcx, args);