Add executable swift test

test/Interpreter/async.swift

@@ -0,0 +1,41 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-build-swift -Xfrontend -enable-experimental-concurrency %s -module-name main -o %t/main
+// RUN: %target-codesign %t/main
+// RUN: %target-run %t/main | %FileCheck %s
+
+// REQUIRES: concurrency
+// UNSUPPORTED: use_os_stdlib
+// UNSUPPORTED: CPU=arm64e
+
+
+func sayHello() async {
+  print("hello")
+}
+
+func sayGeneric<T>(_ msg: T) async {
+  await sayHello()
+  print(msg)
+}
+
+func sayWithClosure(_ action: () async -> ()) async {
+  await action()
+  print("hallo welt")
+}
+
+runAsync {
+  // CHECK: hello
+  await sayHello()
+
+  // CHECK: hello
+  // CHECK: world
+  await sayGeneric("world")
+
+
+  // CHECK: hello
+  // CHECK: and now in german
+  // CHECK: hallo welt
+  await sayWithClosure {
+    await sayHello()
+    print("and now in german")
+  }
+}