test: add test on worker process.exit in async modules

Author: legendecas

test/parallel/test-worker-process-exit-async-module.js

@@ -0,0 +1,10 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+const { Worker } = require('worker_threads');
+
+const w = new Worker(new URL("data:text/javascript,process.exit(1);await new Promise(()=>{ process.exit(2); })"));
+w.on('exit', common.mustCall((code) => {
+  assert.strictEqual(code, 1);
+}));