benchmark: add benchmark for dns.promises.lookup()

Adding this benchmark will let us check the performance implications of
#27081.

benchmark/dns/lookup-promises.js

@@ -0,0 +1,31 @@
+'use strict';
+
+const common = require('../common.js');
+const { lookup } = require('dns').promises;
+
+const bench = common.createBenchmark(main, {
+  name: ['127.0.0.1', '::1'],
+  all: ['true', 'false'],
+  n: [5e6]
+});
+
+function main({ name, n, all }) {
+  if (all === 'true') {
+    const opts = { all: true };
+    bench.start();
+    (async function cb() {
+      for (let i = 0; i < n; i++) {
+        await lookup(name, opts);
+      }
+    })();
+    bench.end(n);
+  } else {
+    bench.start();
+    (async function cb() {
+      for (let i = 0; i < n; i++) {
+        await lookup(name);
+      }
+    })();
+    bench.end(n);
+  }
+}