Log Message:
harfbuzz harfbuzz-icu: updated to 4.2.1

4.2.1
Make sure hb_blob_create_from_file_or_fail() always returns nullptr in case of \ 
failure and not empty blob sometimes. (Khaled Hosny)
Add --passthrough-tables option to hb-subset. (Cosimo Lupo)
Reinstate a pause after basic features in Khmer shaper, fixing a regression \ 
introduced in previous release. (Behdad Esfahbod)
Better handling of Regional_Indicator when shaped with RTL-native scripts, \ 
reverting earlier fix that caused regressions in AAT shaping.