Function checkForBiomesAtLayer 

pub unsafe extern "C" fn checkForBiomesAtLayer(
    ls: *mut LayerStack,
    entry: *mut Layer,
    cache: *mut c_int,
    seed: u64,
    x: c_int,
    z: c_int,
    w: c_uint,
    h: c_uint,
    filter: *const BiomeFilter,
) -> c_int