Combining double caron

[eggrobin]

See L2/24-105, Unicode request for double caron, and https://github.com/unicode-org/sah/issues/297.

UTC-179-C57 Consensus: Provisionally assign U+1ACF COMBINING DOUBLE CARON in the Combining Diacritical Marks Extended block as described in document L2/24-105. [Ref. Section 12 of document L2/24-068]

https://github.com/unicode-org/utc-release-management/issues/116

[181-C60] Consensus: UTC accepts for encoding in Unicode Version 17.0 the following 297 Arabic, Bengali, Han, Kannada, Latin, Oriya, phonetic, Sharada, Tangut, Telugu, and symbol characters for which the code points have previously been provisionally assigned:

    Arabic (40 characters): 088F, FBC3..FBD2, FD90..FD91, FDC8..FDCE, 10EC5..10EC7, 10ED0..10ED8, 10EFA..10EFB
    Bengali (1 character): 09FF
    Han (5 characters): 16FF2..16FF6
    Kannada (1 character): 0CDC
    Latin (2 characters): A7D2, A7D4
    Oriya (2 characters): 0B53..0B54
    Phonetic (30 characters): 1ACF, 1AD0..1ADD, 1AE0..1AEB, A7CE..A7CF, A7F1
    Sharada (8 characters): 11B60..11B67
    Tangut (145 characters): 187F8..187FF, 18D09..18D1E, 18D80..18DF2
    Telugu (1 character): 0C5C
    Symbols (62 characters): 2B96, 1CCFA..1CCFC, 1CEBA..1CED0, 1CEE0..1CEF0, 1F777..1F77A, 1F8D0..1F8D8, 1FA54..1FA57, 1FBFA

[markusicu]

lgtm