j2k: flatten test cases and testData directory structure

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

j2k/testData/fileOrElement/newClassExpression/genericClassInvocation.java

@@ -0,0 +1,9 @@
+//file
+import java.util.List;
+import java.util.ArrayList;
+
+class User {
+  void main() {
+    List<String> list = new ArrayList<String>();
+  }
+}