j2k: flatten test cases and testData directory structure

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

j2k/testData/fileOrElement/function/overrideObject3.java

@@ -0,0 +1,14 @@
+//file
+class Base {
+    @Override
+    public boolean equals(Object o) {
+        return super.equals(o);
+    }
+}
+
+class X extends Base {
+    @Override
+    public boolean equals(Object o) {
+        return super.equals(o);
+    }
+}