UnixNativeDispatcher.c current has this:

#if (_POSIX_C_SOURCE >= 200809L) || defined(__solaris__)
    (*env)->SetLongField(env, attrs, attrs_st_atime_nsec, (jlong)buf->st_atim.tv_nsec);
    (*env)->SetLongField(env, attrs, attrs_st_mtime_nsec, (jlong)buf->st_mtim.tv_nsec);
    (*env)->SetLongField(env, attrs, attrs_st_ctime_nsec, (jlong)buf->st_ctim.tv_nsec);
#endif

but this dates back to older build platforms and can be cleaned up.