j2k: flatten test cases and testData directory structure

Move j2k/test/tests -> j2k/tests, j2k/test/testData -> j2k/testData

j2k/testData/fileOrElement/switch/fallDown.kt

@@ -0,0 +1,17 @@
+package switch_demo
+
+public class SwitchDemo {
+    class object {
+        public fun main(args: Array<String>) {
+            val month = 8
+            val monthString: String
+            when (month) {
+                1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 -> monthString = "December"
+                else -> monthString = "Invalid month"
+            }
+            System.out.println(monthString)
+        }
+    }
+}
+
+fun main(args: Array<String>) = SwitchDemo.main(args)