osx : fix syscalls

vgui2/src/system_posix.cpp

@@ -30,6 +30,8 @@
 
 #ifdef OSX
 #include <Carbon/Carbon.h>
+#include <sys/param.h>
+#include <sys/mount.h>
 #elif defined(LINUX)
 #include <sys/vfs.h>
 #endif
@@ -583,8 +585,14 @@ int CSystem::GetAvailableDrives(char *buf, int bufLen)
 //-----------------------------------------------------------------------------
 double CSystem::GetFreeDiskSpace(const char *path)
 {
+#if __DARWIN_ONLY_64_BIT_INO_T
+    // MoeMod: newer macOS only support 64bit, so no statfs64 is provided
+    struct statfs buf;
+    int ret = statfs( path, &buf );
+#else
 	struct statfs64 buf;
 	int ret = statfs64( path, &buf );
+#endif
 	if ( ret < 0 )
 		return 0.0;
 	return (double) ( buf.f_bsize * buf.f_bfree );