Function RpcServerRegisterIfEx 

pub unsafe extern "system" fn RpcServerRegisterIfEx(
    ifspec: *const c_void,
    mgrtypeuuid: *const GUID,
    mgrepv: *const c_void,
    flags: u32,
    maxcalls: u32,
    ifcallback: RPC_IF_CALLBACK_FN,
) -> RPC_STATUS