Function s2n_tls_sys::s2n_mem_set_callbacks

pub unsafe extern "C" fn s2n_mem_set_callbacks(
    mem_init_callback: s2n_mem_init_callback, 
    mem_cleanup_callback: s2n_mem_cleanup_callback, 
    mem_malloc_callback: s2n_mem_malloc_callback, 
    mem_free_callback: s2n_mem_free_callback
) -> c_int