Reader Coffee Addict informs me that over at the Internet Movie Database (IMDb) page for the movie Magneto, an X-Men spinoff, Dr Mahathir is listed in the plot outline of movie! From IMDb (here's the screenshot):
Haha! Someone over at IMDb really has a good sense of humour.
(Thanks Coffee Addict)
Update: Mahathir has been added to the credits! LOL