Add unistd.h files for mingw/Unix compatibility.
diff --git a/include/Makefile.in b/include/Makefile.in
index e9ab068..e7948a4 100644
--- a/include/Makefile.in
+++ b/include/Makefile.in
@@ -194,8 +194,10 @@
msvcrt/sys/stat.h \
msvcrt/sys/timeb.h \
msvcrt/sys/types.h \
+ msvcrt/sys/unistd.h \
msvcrt/sys/utime.h \
msvcrt/time.h \
+ msvcrt/unistd.h \
msvcrt/wchar.h \
msvcrt/wctype.h
diff --git a/include/msvcrt/sys/unistd.h b/include/msvcrt/sys/unistd.h
new file mode 100644
index 0000000..1e823fb
--- /dev/null
+++ b/include/msvcrt/sys/unistd.h
@@ -0,0 +1 @@
+#include <unistd.h>
diff --git a/include/msvcrt/unistd.h b/include/msvcrt/unistd.h
new file mode 100644
index 0000000..eca5c5e
--- /dev/null
+++ b/include/msvcrt/unistd.h
@@ -0,0 +1,2 @@
+#include <io.h>
+#include <process.h>
