Add missing header for general unix compat

S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH are defined in
<sys/stat.h> as per POSIX

Author: krono

platforms/Cross/plugins/FilePlugin/sqFilePluginBasicPrims.c

@@ -35,6 +35,7 @@
 
 #ifndef NO_STD_FILE_SUPPORT
 
+#include <sys/stat.h>
 #include <fcntl.h>
 #include <limits.h>
 #include <stdio.h>