j2k: flatten test cases and testData directory structure

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

j2k/testData/fileOrElement/annotations/annotationInterface3.java

@@ -0,0 +1,14 @@
+@interface Anon {
+    String value();
+
+    enum E {
+        A, B
+    }
+
+    E field = E.A;
+}
+
+@Anon("a")
+interface I {
+    Anon.E e = Anon.field;
+}