Fix issue 158.

src/nvthread/nvthread.cpp

@@ -8,8 +8,21 @@
 #  include "Win32.h"
 #elif NV_OS_UNIX
 #  include <sys/types.h>
-#  include <sys/param.h>
 #  include <sys/sysctl.h>
+#  include <unistd.h>
+#elif NV_OS_DARWIN
+#  import <stdio.h>
+#  import <string.h>
+#  import <mach/mach_host.h>
+#  import <sys/sysctl.h>
+
+#  include <CoreFoundation/CoreFoundation.h>
+
+#  include <assert.h>
+#  include <errno.h>
+#  include <stdlib.h>
+#  include <string.h>
+#  include <syslog.h>
 #endif
 
 using namespace nv;