[HarfBuzz] feature "execution" order

[Martin Hosken]

Dear Bob,

> I'm copy/pasting some stuff I wrote a while back in another thread.  In
> general, look for add_gsub_pause in harfbuzz source code and you get to the
> place you need.

Which, from reading the code for arabic results in the following feature order. Merged features are listed on the same line. Each line is a run of the lookups for the given features:

ccmp, locl
isol
fina
fin2
fin3
medi
med2
init
rlig
calt
mset

HTH,
Yours,
Martin