j2k: flatten test cases and testData directory structure

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

j2k/testData/fileOrElement/function/overrideObject3.kt

@@ -0,0 +1,11 @@
+open class Base {
+    override fun equals(o: Any?): Boolean {
+        return super.equals(o)
+    }
+}
+
+class X : Base() {
+    override fun equals(o: Any?): Boolean {
+        return super.equals(o)
+    }
+}