void ClassLoader::add_to_app_classpath_entries(JavaThread* current,
                                               const char* path,
                                               ClassPathEntry* entry,
                                               bool check_for_duplicates) {

The path parameter is unused since  the check for its existence was removed by JDK-8193213:

-  } else {
-    if (!os::dir_is_empty(path)) {
-      tty->print_cr("Error: non-empty directory '%s'", path);
-      exit_with_path_failure("Cannot have non-empty directory in app classpaths", NULL);
-    }