Remove use of sys/poll.h on mingw

ChangeLog

+Fri Oct 24 14:09:23 BST Daniel P. Berrange <berrange@redhat.com>
+
+	* configure.in: Add check for sys/poll.h
+	* examples/domain-events/events-c/event-test.c: Stub out
+	no-op main() on platforms without sys/poll.h
+	* src/libvirt.c, src/remote_internal.c: Remove redundant
+	include of sys/poll.h breaking mingw
+
 Fri Oct 24 13:04:23 BST Daniel P. Berrange <berrange@redhat.com>
 
 	* src/storage_conf.c: Remove <tab> character

configure.in

@@ -70,7 +70,7 @@ dnl Availability of various common functions (non-fatal if missing).
 AC_CHECK_FUNCS([cfmakeraw regexec uname sched_getaffinity getuid getgid])
 
 dnl Availability of various common headers (non-fatal if missing).
-AC_CHECK_HEADERS([pwd.h paths.h regex.h sys/syslimits.h sys/utsname.h sys/wait.h winsock2.h sched.h termios.h])
+AC_CHECK_HEADERS([pwd.h paths.h regex.h sys/syslimits.h sys/utsname.h sys/wait.h winsock2.h sched.h termios.h sys/poll.h])
 
 dnl Where are the XDR functions?
 dnl If portablexdr is installed, prefer that.

examples/domain-events/events-c/event-test.c

 #include <config.h>
+
 #include <stdio.h>
 #include <string.h>
+
+#if HAVE_SYS_POLL_H
 #include <sys/types.h>
 #include <sys/poll.h>
 #include <libvirt/libvirt.h>
@@ -259,3 +262,9 @@ int main(int argc, char **argv)
     return 0;
 }
 
+#else
+int main(void) {
+    printf("event-test program not available without sys/poll.h support\n");
+    return 1;
+}
+#endif

src/libvirt.c

@@ -16,7 +16,6 @@
 #include <string.h>
 #include <sys/types.h>
 #include <sys/stat.h>
-#include <sys/poll.h>
 #include <unistd.h>
 #include <assert.h>
 #ifdef HAVE_SYS_WAIT_H

src/remote_internal.c

@@ -34,7 +34,6 @@
 #include <signal.h>
 #include <sys/types.h>
 #include <sys/stat.h>
-#include <sys/poll.h>
 #include <fcntl.h>
 
 #ifdef HAVE_SYS_WAIT_H