tests: check decoding of setfsuid syscall

* tests/setfsugid.c: New file.
* tests/setfsuid.c: New file.
* tests/setfsuid.test: New test.
* tests/.gitignore: Add setfsuid.
* tests/Makefile.am (check_PROGRAMS): Likewise.
(DECODER_TESTS): Add setfsuid.test.
(EXTRA_DIST): Add setfsugid.c.
diff --git a/tests/setfsuid.c b/tests/setfsuid.c
new file mode 100644
index 0000000..7c77f50
--- /dev/null
+++ b/tests/setfsuid.c
@@ -0,0 +1,23 @@
+#include "tests.h"
+#include <sys/syscall.h>
+
+#ifdef __NR_setfsuid
+
+# define SYSCALL_NR	__NR_setfsuid
+# define SYSCALL_NAME	"setfsuid"
+
+# if defined __NR_setfsuid32 && __NR_setfsuid != __NR_setfsuid32
+#  define UGID_TYPE	short
+#  define GETUGID	syscall(__NR_geteuid)
+# else
+#  define UGID_TYPE	int
+#  define GETUGID	geteuid()
+# endif
+
+# include "setfsugid.c"
+
+#else
+
+SKIP_MAIN_UNDEFINED("__NR_setfsuid")
+
+#endif