"Unidecode" functionality in Emacs

[John Mastro]

There are "Unidecode" packages for Perl[1], Python[2], and Emacs[3]
(derived from one another in that order). They each transliterate
Unicode text to ASCII, e.g.:

    (unidecode "Déjà vu")
    ;=> "Deja vu"
    (unidecode "北亰")
    ;=> "Bei Jing "

Does Emacs have equivalent functionality built-in?

[ The context for this is that I recently submitted a change to the
  MELPA recipe, and Steve Purcell mentioned[4] that he would be
  surprised if Emacs doesn't already have such functionality. ]

Thanks for any pointers

        John

[1]: http://search.cpan.org/~sburke/Text-Unidecode-1.30/lib/Text/Unidecode.pm
[2]: https://pypi.python.org/pypi/Unidecode
[3]: https://github.com/sindikat/unidecode
[4]: https://github.com/melpa/melpa/pull/5351#issuecomment-373966218