Function gfrfov_c 

pub unsafe extern "C" fn gfrfov_c(
    inst: *mut u8,
    raydir: *mut f64,
    rframe: *mut u8,
    abcorr: *mut u8,
    obsrvr: *mut u8,
    step: f64,
    cnfine: *mut _SpiceCell,
    result: *mut _SpiceCell,
)