chore(bench_util): update README example (denoland#13226)

bench_util/README.md

@@ -9,19 +9,28 @@ use deno_bench_util::bench_js_sync};
 
 use deno_core::op_sync;
 use deno_core::serialize_op_result;
+use deno_core::Extension;
 use deno_core::JsRuntime;
 use deno_core::Op;
 use deno_core::OpState;
 
-fn setup(runtime: &mut JsRuntime) {
- runtime.register_op("nop", |state, _| {
- Op::Sync(serialize_op_result(Ok(9), state))
- });
- runtime.sync_ops_cache();
+fn setup() -> Vec<Extension> {
+ let custom_ext = Extension::builder()
+ .ops(vec![
+ ("op_nop", |state, _| {
+ Op::Sync(serialize_op_result(Ok(9), state))
+ }),
+ ])
+ .build();
+
+ vec![
+ // deno_{ext}::init(...),
+ custom_ext,
+ ]
 }
 
 fn bench_op_nop(b: &mut Bencher) {
- bench_js_sync(b, r#"Deno.core.opSync("nop", null, null, null);"#, setup);
+ bench_js_sync(b, r#"Deno.core.opSync("op_nop", null, null);"#, setup);
 }
 
 benchmark_group!(benches, bench_op_nop);