pub fn remove_deleted_glyphs(buffer: &mut hb_buffer_t)
HB: hb_aat_layout_remove_deleted_glyphs
See https://github.com/harfbuzz/harfbuzz/blob/2c22a65f0cb99544c36580b9703a43b5dc97a9e1/src/hb-aat-layout.cc#L337