j2k: flatten test cases and testData directory structure

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

j2k/testData/fileOrElement/tryWithResource/Multiline.kt

@@ -0,0 +1,12 @@
+import java.io.*
+
+public class C {
+    throws(javaClass<IOException>())
+    fun foo() {
+        ByteArrayInputStream(ByteArray(10)).use { stream ->
+            // reading something
+            val c = stream.read()
+            System.out.println(c)
+        }
+    }
+}