RazrFalcon
UNSAFE_TO_CONCAT inaccessible?
the UNSAFE_TO_CONCAT glyph info flag does not appear to be accessible to users of the library.
for UNSAFE_TO_BREAK, there is a method on hb_glyph_info_t.
there is no such method for UNSAFE_TO_CONCAT.
i'm not entirely sure why the mask field of hb_glyph_info_t and the pub mod glyph_flag in hb/buffer.rs are private. but this also means that SAFE_TO_INSERT_TATWEEL is inaccessible, as there is no accessor method for that either.
maybe i'm missing something, but https://docs.rs/rustybuzz/latest/rustybuzz/?search=UNSAFE_TO_CONCAT only lists rustybuzz::BufferFlags::PRODUCE_UNSAFE_TO_CONCAT. which suggests to me that the feature is usable. i tried it with some sample text, and the output does seem reasonable.
If I remember correctly I added the UNSAFE_TO_CONCAT and SAFE_TO_INSERT_TATWEEL as part of the backporting process, but it's definitely possible that I forgot to expose them properly. So it's most likely just by accident.
