Fix checking whether kqueue is available.

It seems like the newer OS X versions don't put headers into the
system include directories. Switch to using a test file instead.

configure

@@ -382,22 +382,8 @@ print "yes\n" if $config{HAS_STRLCPY} eq "true";
 print "no\n" if $config{HAS_STRLCPY} eq "false";
 
 printf "Checking if kqueue exists... ";
-$has_kqueue = 0;
-$fail = 0;
-open(KQUEUE, "</usr/include/sys/event.h") or $fail = 1;
-if (!$fail) {
-	while (defined(my $line = <KQUEUE>)) {
-		chomp($line);
-		# try and find the delcaration of:
-		# int kqueue(void);
-		if ($line =~ /int(\0x9|\s)+kqueue/) {
-			$has_kqueue = 1;
-		}
-	}
-	close(KQUEUE);
-}
-print "yes\n" if $has_kqueue == 1;
-print "no\n" if $has_kqueue == 0;
+$has_kqueue = test_compile('kqueue');
+print $has_kqueue ? "yes\n" : "no\n";
 
 printf "Checking for epoll support... ";
 $has_epoll = test_compile('epoll');

make/check_kqueue.cpp

@@ -0,0 +1,26 @@
+/*
+ * InspIRCd -- Internet Relay Chat Daemon
+ *
+ *   Copyright (C) 2015 Peter Powell <petpow@saberuk.com>
+ *
+ * This file is part of InspIRCd.  InspIRCd is free software: you can
+ * redistribute it and/or modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#include <sys/types.h>
+#include <sys/event.h>
+
+int main() {
+	int fd = kqueue();
+	return (fd < 0);
+}