test: add test for cluster benchmarks

Add minimal test to make sure cluster benchmark code runs.

PR-URL: https://github.com/nodejs/node/pull/14812
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>
Reviewed-By: Yuta Hiroto <hello@about-hiroppy.com>

test/parallel/test-benchmark-cluster.js

@@ -0,0 +1,22 @@
+'use strict';
+
+require('../common');
+
+// Minimal test for cluster benchmarks. This makes sure the benchmarks aren't
+// horribly broken but nothing more than that.
+
+const assert = require('assert');
+const fork = require('child_process').fork;
+const path = require('path');
+
+const runjs = path.join(__dirname, '..', '..', 'benchmark', 'run.js');
+const argv = ['--set', 'n=1',
+              '--set', 'payload=string',
+              '--set', 'sendsPerBroadcast=1',
+              'cluster'];
+
+const child = fork(runjs, argv);
+child.on('exit', (code, signal) => {
+  assert.strictEqual(code, 0);
+  assert.strictEqual(signal, null);
+});