Log Message:
harfbuzz{,-icu}: update to 3.4.0

Overview of changes leading to 3.4.0
Sunday, February 13, 2022
====================================
- Perform sanity checks on shaping results is now part of “harfbuzz” library
  and can be enabled by setting the buffer flag HB_BUFFER_FLAG_VERIFY.
  (Behdad Esfahbod)
- Arabic Mark Transient Reordering Algorithm have been updated to revision 6.
  (Khaled Hosny)
- ISO 15924 code for mathematical notation, ‘Zmth’, now maps to the OpenType
  ‘math’ tag. (Alexis King)
- It is now possible to get at once all math kerning values for a given glyph
  at a given corner. (Alexis King)
- Fix locale_t portability issues on systems the typdef’s it to a void pointer.
  (Behdad Esfahbod)

- New API:
+HB_BUFFER_FLAG_VERIFY
+HB_OT_TAG_MATH_SCRIPT
+HB_SCRIPT_MATH
+hb_ot_math_kern_entry_t
+hb_ot_math_get_glyph_kernings

- Deprecated API
+HB_OT_MATH_SCRIPT