j2k: flatten test cases and testData directory structure

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

j2k/testData/fileOrElement/enum/fieldsWithPrimaryPrivateConstructor.java

@@ -0,0 +1,14 @@
+//class
+enum Color {
+    WHITE(21), BLACK(22), RED(23), YELLOW(24), BLUE(25);
+
+    private int code;
+
+    private Color(int c) {
+        code = c;
+    }
+
+    public int getCode() {
+        return code;
+    }
+}