[nginx] Fixed build on Linux with x32 ABI.

[Maxim Dounin]

details:   http://hg.nginx.org/nginx/rev/7f4ec5bfb715
branches:  
changeset: 5255:7f4ec5bfb715
user:      Maxim Dounin <mdounin at mdounin.ru>
date:      Wed Jun 26 15:47:27 2013 +0400
description:
Fixed build on Linux with x32 ABI.

On Linux x32 inclusion of sys/sysctl.h produces an error.  As sysctl() is
only used by rtsig event method code, which is legacy and not compiled
in by default on modern linuxes, the sys/sysctl.h file now only included
if rtsig support is enabled.

Based on patch by Serguei I. Ivantsov.

diffstat:

 src/os/unix/ngx_linux_config.h |  9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diffs (30 lines):

diff --git a/src/os/unix/ngx_linux_config.h b/src/os/unix/ngx_linux_config.h
--- a/src/os/unix/ngx_linux_config.h
+++ b/src/os/unix/ngx_linux_config.h
@@ -51,7 +51,6 @@
 #include <malloc.h>             /* memalign() */
 #include <limits.h>             /* IOV_MAX */
 #include <sys/ioctl.h>
-#include <sys/sysctl.h>
 #include <crypt.h>
 #include <sys/utsname.h>        /* uname() */
 
@@ -77,11 +76,17 @@ extern ssize_t sendfile(int s, int fd, i
 #endif
 
 
-#if (NGX_HAVE_POLL || NGX_HAVE_RTSIG)
+#if (NGX_HAVE_POLL)
 #include <poll.h>
 #endif
 
 
+#if (NGX_HAVE_RTSIG)
+#include <poll.h>
+#include <sys/sysctl.h>
+#endif
+
+
 #if (NGX_HAVE_EPOLL)
 #include <sys/epoll.h>
 #endif