coretext_aat was a temporary shaper to redirect shaping of AAT fonts
to CoreText and leaving the rest for HarfBuzz. As HarfBuzz now supports
AAT and Chrome now actually ships that on a stable version on macOS,
we no longer care about such use-case. If a client really wants 100%
metrics compatibility with CoreText better to use it directly or through
our API. Replicating the same behavior still is possible using
hb_shape_full, something we don't care or like to offer anymore.
Fixes https://github.com/harfbuzz/harfbuzz/issues/1478
This is a higher-priority shaper than default shaper ("ot"), but
only picks up fonts that have AAT "morx"/"mort" table.
Note that for this to work the font face's get_table() implementation
should know how to return the full font blob.
Based on patch from Konstantin Ritt.
Ebrahim Byagowi
Behdad Esfahbod
Konstantin Ritt