Fix bug #5438102 Double Arabic harakat overlap instead of stack In TextView

IMPORTANT: this change needs two patches for Harfbuzz:
- one concerning hb_utf16_script_run_prev() which was not returning the correct "previous" script
- one for the "script_properties" table that was missing Arabic code point ranges and declaring
HB_Script_Inherited instead of HB_Script_Arabic

The current change is doing the following:
- pass the correct typeface for Harbuzz shaping (depending on the script of the run)
- offset correctly the glyphIDs returned by Harfbuzz

We need to offset the glyphsID as Harfbuzz will return local glyphIDs (meaning in the
local range of the font used for shapping).

We then cannot use those glyphIDs when we are using a fallback Font (Arabic, Hebrews...)
because the FontRenderer needs glyphIDs in the range of all the Fonts (including the fallbacks)

Change-Id: I494897435bbc59293b02392ee2059cebcdf0e571
3 files changed