Fix compiler warnings when compiled against musl libc

musl libc is complaining when <sys/poll.h> is used instead of <poll.h>
so change this.

This issue was reported for OpenWrt/LEDE where musl libc is the standard
C library instead of e.g. glibc, see the following link for the original PR:
https://github.com/openwrt/packages/pull/4263

Signed-off-by: Philip Prindeville <philipp@redfish-solutions.com>
Signed-off-by: Michael Heimpold <mhei@heimpold.de>

--

v3: refined checks/fallback paths as suggested by @bukka

v2: rebased to resolve merge conflict in main/php_network.h

v1: initial PR

configure.in

@@ -494,6 +494,7 @@ limits.h \
 locale.h \
 monetary.h \
 netdb.h \
+poll.h \
 pwd.h \
 resolv.h \
 signal.h \

main/fastcgi.c

@@ -76,7 +76,9 @@ static int is_impersonate = 0;
 # include <netdb.h>
 # include <signal.h>
 
-# if defined(HAVE_SYS_POLL_H) && defined(HAVE_POLL)
+# if defined(HAVE_POLL_H) && defined(HAVE_POLL)
+#  include <poll.h>
+# elif defined(HAVE_SYS_POLL_H) && defined(HAVE_POLL)
 #  include <sys/poll.h>
 # endif
 # if defined(HAVE_SYS_SELECT_H)
@@ -1427,7 +1429,7 @@ int fcgi_accept_request(fcgi_request *req)
 				break;
 #else
 				if (req->fd >= 0) {
-#if defined(HAVE_SYS_POLL_H) && defined(HAVE_POLL)
+#if defined(HAVE_POLL)
 					struct pollfd fds;
 					int ret;
 

main/network.c

@@ -51,7 +51,9 @@
 #ifdef HAVE_SYS_SELECT_H
 #include <sys/select.h>
 #endif
-#if HAVE_SYS_POLL_H
+#if HAVE_POLL_H
+#include <poll.h>
+#elif HAVE_SYS_POLL_H
 #include <sys/poll.h>
 #endif
 

main/php_network.h

@@ -120,8 +120,12 @@ typedef int php_socket_t;
 /* uncomment this to debug poll(2) emulation on systems that have poll(2) */
 /* #define PHP_USE_POLL_2_EMULATION 1 */
 
-#if defined(HAVE_SYS_POLL_H) && defined(HAVE_POLL)
-# include <poll.h>
+#if defined(HAVE_POLL)
+# if defined(HAVE_POLL_H)
+#  include <poll.h>
+# elif defined(HAVE_SYS_POLL_H)
+#  include <sys/poll.h>
+# endif
 typedef struct pollfd php_pollfd;
 #else
 typedef struct _php_pollfd {