Modifier voiceless implosives

[eggrobin]

See L2/24-130, Unicode request for modifier voiceless implosive letters, and https://github.com/unicode-org/sah/issues/442.

UTC-180-C32 Consensus: Provisionally assign six modifier letter code points U+1DFFA MODIFIER LETTER SMALL C WITH HOOK, U+1DFFB MODIFIER LETTER SMALL K WITH HOOK, U+1DFFC MODIFIER LETTER SMALL P WITH HOOK, U+1DFFD MODIFIER LETTER SMALL Q WITH HOOK, U+1DFFE MODIFIER LETTER SMALL T WITH HOOK, U+1DFFF MODIFIER LETTER SMALL T WITH HOOK AND RETROFLEX HOOK in the Latin Extended-G block as described in L2/24-130R. [Ref. Section 11 of document L2/24-166]

https://github.com/unicode-org/utc-release-management/issues/121

[roozbehp]

lgtm except it's not clear to me whether there should be DoNotEmit entries for one character or for six: unicode-org/sah#442 (comment)

Just one. There is no "combining attached hook above" for the other five.