j2k: flatten test cases and testData directory structure

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

j2k/testData/fileOrElement/newClassExpression/newAnonymousClass2.java

@@ -0,0 +1,13 @@
+//file
+abstract class A {}
+
+class C {
+    void foo() {
+        A a = new A() {
+            @Override
+            public String toString() {
+                return "a";
+            }
+        };
+    }
+}