[HarfBuzz] "Old HarfBuzz" maintenance

[Behdad Esfahbod]

Hi Lars and Simon,

There are a few simple bugs against the old HarfBuzz code that you may be
interested in fixing.  Most have patches.  In particular:

Resource leak in tibetan_shape_syllable
https://bugs.freedesktop.org/show_bug.cgi?id=31992

Resource leak ::Lookup_ChainContextSubst2
https://bugs.freedesktop.org/show_bug.cgi?id=31993

Resource leak ::Lookup_ChainContextPos2
https://bugs.freedesktop.org/show_bug.cgi?id=31994

Resource leak in ::HB_ArabicShape
https://bugs.freedesktop.org/show_bug.cgi?id=31995


There's also this one:

https://bugs.freedesktop.org/show_bug.cgi?id=30319


And a few that I WONTFIX'ed since I don't see myself fixing them:

https://bugs.freedesktop.org/show_bug.cgi?id=27485
https://bugs.freedesktop.org/show_bug.cgi?id=16580
https://bugs.freedesktop.org/show_bug.cgi?id=31003
https://bugs.freedesktop.org/show_bug.cgi?id=17636
https://bugs.freedesktop.org/show_bug.cgi?id=23805


Cheers,
behdad