test: increase runInAsyncScope() coverage

We don't appear to have any test coverage for passing the `thisArg`
argument to `runInAsyncScope()`. Test coverage stats seem to bear this
out. Add a test for it.

PR-URL: #36624
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>

test/parallel/test-async-hooks-run-in-async-scope-this-arg.js

@@ -0,0 +1,17 @@
+'use strict';
+
+// Test that passing thisArg to runInAsyncScope() works.
+
+const common = require('../common');
+const assert = require('assert');
+const { AsyncResource } = require('async_hooks');
+
+const thisArg = {};
+
+const res = new AsyncResource('fhqwhgads');
+
+function callback() {
+  assert.strictEqual(this, thisArg);
+}
+
+res.runInAsyncScope(common.mustCall(callback), thisArg);