The only thing we could potentially do here in case of error
returned is to complain to error log, but we don't have log
structure available here due to interface limitations.

Prodded by Coverity.

It is available via winetricks which makes it still usable, and has
an old crtdefs.h which uses _CRT_SECURE_NO_DEPRECATE instead of
_CRT_SECURE_NO_WARNINGS to suppress warnings.

Reported by HAYASHI Kentaro,
http://mailman.nginx.org/pipermail/nginx-devel/2012-August/002542.html

If ngx_spawn_process() failed while starting a process, the process
handle was closed but left non-NULL in the ngx_processes[] array.
The handle later was used in WaitForMultipleObjects() (if there
were multiple worker processes configured and at least one worker
process was started successfully), resulting in infinite loop.

Reported by Ricardo V G:
http://mailman.nginx.org/pipermail/nginx-devel/2012-July/002494.html

HP-UX needs _HPUX_ALT_XOPEN_SOCKET_API to be defined to be able to
use various POSIX versions of networking functions.  Notably sendmsg()
resulted in "sendmsg() failed (9: Bad file number)" alerts without it.

See xopen_networking(7) for more details.

Poll event method needs ngx_cycle->files to work, and use of ngx_exit_cycle
without files set caused null pointer dereference in resolver's cleanup
on udp socket close.

This includes trailings dots and spaces, NTFS streams (and short names, as
previously checked).  The checks are now also done in ngx_file_info(), thus
allowing to use the "try_files" directive to protect external scripts.