Function ttf_parser::tables::cff::cff1::parse_cid_local_subrs

fn parse_cid_local_subrs<'a>(
    data: &'a [u8],
    glyph_id: GlyphId,
    cid: &CIDMetadata<'_>,
) -> Option<Index<'a>>

In CID fonts, to get local subroutines we have to:

1. Find Font DICT index via FDSelect by GID.
2. Get Font DICT data from FDArray using this index.
3. Get a Private DICT offset from a Font DICT.
4. Get a local subroutine offset from Private DICT.
5. Parse a local subroutine at offset.