[HarfBuzz] what not to indic shape

[Martin Hosken]

Dear Behdad,

Here is a list of scripts that I think shouldn't be using the indic shaper. Justification of simple means that there is no reordering or conjuncts involved and that there is probably no actual shaping (so just generic shaping will be sufficient).

BATAK:		? Simple
BRAHMI:		? Simple
HANUNOO:	? Simple
KAYAH_LI:	Simple
LAO:		See Thai
LIMBU:		Simple
MEETEI_MAYEK:	? Simple
MYANMAR:	Current implementations do not have complex shaping. The current indic shaper is inappropriate. This is a temporary measure. Ideally the font should be queried for a key feature like blwf. If missing, then use generic shaping else use either fixed indic or myanmar specific.
PHAGS_PA:	Simple
SAURASHTRA:	? Simple
SYLOTI_NAGRI:	Simple
TAGALOG:	Simple
TAGBANWA:	Simple
TAI_LE:		Simple
TAI_VIET:	See Thai
THAI:		No reordering, no conjuncts, some ligation, generic shaping sufficient. Note that for the Thai class of scripts reordering prevowels would be wrong.
TIBETAN:	Subjoined characters have their own codes.

HTH,
Martin