Function ncclAllReduce

pub unsafe extern "C" fn ncclAllReduce(
    sendbuff: *const c_void,
    recvbuff: *mut c_void,
    count: usize,
    datatype: ncclDataType_t,
    op: ncclRedOp_t,
    comm: ncclComm_t,
    stream: cudaStream_t,
) -> ncclResult_t