Update.

test/await/async_concurrent.wren

@@ -0,0 +1,18 @@
+import "scheduler" for Scheduler, Future
+import "timer" for Timer
+
+var order = []
+
+var task1 = async {
+  await Timer.sleep(2)
+  order.add("task1")
+}
+
+var task2 = async {
+  await Timer.sleep(1)
+  order.add("task2")
+}
+
+await task1
+await task2
+System.print(order) // expect: [task2, task1]