Function GxB_Matrix_split 

pub unsafe extern "C" fn GxB_Matrix_split(
    Tiles: *mut GrB_Matrix,
    m: GrB_Index,
    n: GrB_Index,
    Tile_nrows: *const GrB_Index,
    Tile_ncols: *const GrB_Index,
    A: GrB_Matrix,
    desc: GrB_Descriptor,
) -> GrB_Info