[HarfBuzz] HarfBuzz shaping of R2L text

[Eli Zaretskii]

> Date: Sun, 2 Jun 2019 18:35:07 +0100
> From: Richard Wordingham <richard.wordingham at ntlworld.com>
> 
> It looks as though you will have to resort to Padauk for Windows 7
> Uniscribe shaping for Myanmar, and trust that you don't accidentally
> pick up a Graphite shaper.

With Emacs learning to shape text via HarfBuzz, Uniscribe is about to
become deprecated for Emacs on Windows.  Which is good, since
Microsoft want the users to move away of Uniscribe, and the
replacement DirectWrite will probably never be supported by Emacs.

The version of HarfBuzz I built on Windows and am using with Emacs has
Graphite support, so I reckon I don't have to worry about picking up a
Graphite shaper?