Patched to compile on FreeBSD.
diff --git a/src/filesystem/unix/SDL_sysfilesystem.c b/src/filesystem/unix/SDL_sysfilesystem.c
index 1798f3e..659d126 100644
--- a/src/filesystem/unix/SDL_sysfilesystem.c
+++ b/src/filesystem/unix/SDL_sysfilesystem.c
@@ -29,6 +29,7 @@
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/types.h>
+#include <limits.h>
#ifdef __FREEBSD__
#include <sys/sysctl.h>