* [aat] Correct array indexing when looking up actions in KerxSubTableFormat4.
- For action_type 0 and 1, there are 2 values per action record; for action_type 2, there are 4. So we need to account for these factors when indexing into the ankrData array.
Fixes https://github.com/harfbuzz/harfbuzz/issues/2531.