Mingw porting fix.

diff --git a/configure.ac b/configure.ac
index f7e7ec1..699c82f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1017,6 +1017,8 @@
 	sys/sysctl.h \
 	sys/time.h \
 	sys/times.h \
+	sys/uio.h \
+	sys/un.h \
 	sys/user.h \
 	sys/v86.h \
 	sys/v86intr.h \