[Native][tests] Move golden data outside of Gradle build file

kotlin-native/backend.native/tests/runtime/basic/driver_opt.kt

@@ -0,0 +1,9 @@
+/*
+ * Copyright 2010-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the LICENSE file.
+ */
+
+// TODO: remove kotlin_native.io once overrides are in place.
+fun main(args : Array<String>) {
+    println("Hello, world!")
+}