aio/unix: Use signal.sival which is standard

[Sergey Kandaurov]

> On 18 Jan 2019, at 10:39, Sepherosa Ziehau <sepherosa at gmail.com> wrote:
> 
> Hi,
> 
>> diff --git a/src/os/unix/ngx_freebsd_config.h b/src/os/unix/ngx_freebsd_config.h
>> --- a/src/os/unix/ngx_freebsd_config.h
>> +++ b/src/os/unix/ngx_freebsd_config.h
>> @@ -91,6 +91,10 @@
>> #if (NGX_HAVE_FILE_AIO)
>> #include <aio.h>
>> typedef struct aiocb  ngx_aiocb_t;
>> +
>> +#if (__FreeBSD_version < 700005 && !defined __DragonFly__)
>> +#define sival_ptr                 sigval_ptr
>> +#endif
>> #endif
> 
> Will the following code be more straightforward?
> #if defined(__FreeBSD__) && (__FreeBSD_version < 700005)
> #define sival_ptr sigval_ptr
> #endif

This won't work.  __FreeBSD__ and__FreeBSD_version
are defined for DragonFly in src/core/ngx_config.h.

-- 
Sergey Kandaurov