Merge pull request #43 from MggMuggins/master

Imp va_arg for fcntl; fcntl test

tests/Makefile

@@ -10,6 +10,7 @@ BINS=\
 	dup \
 	error \
 	fchdir \
+	fcntl \
 	fsync \
 	ftruncate \
 	getid \

tests/fcntl.c

@@ -0,0 +1,13 @@
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+
+int main() {
+    //Lose our fd and pull it again
+    creat("fcntl.out", 0777);
+    int newfd = open("fcntl.out", 0);
+    int newfd2 = fcntl(newfd, F_DUPFD, 0);
+    printf("fd %d duped into fd %d\n", newfd, newfd2);
+    close(newfd);
+    close(newfd2);
+}