[PATCH v2] msvc: Fix compilation error due to missing mktemp() declaration

Commit d1b6e6e (win32: use our own dirent.h, 2010-11-23) removed
the compat/vcbuild/include/dirent.h compatibility header file.
This file, among other things, included the <io.h> system header
file which provides the declaration of the mktemp() function.

In order to fix the compilation error, we add an include directive
for <io.h> to the compat/mingw.h header.

Signed-off-by: Ramsay Jones <redacted>
---

Change from v1:
    - add #include to compat/mingw.h rather than compat/vcbuild/include/unistd.h

ATB,
Ramsay Jones

 compat/mingw.h |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/compat/mingw.h b/compat/mingw.h
index cafc1eb..1c6bc02 100644
--- a/compat/mingw.h
+++ b/compat/mingw.h

@@ -1,5 +1,6 @@
 #include <winsock2.h>
 #include <ws2tcpip.h>
+#include <io.h>
 
 /*
  * things that are not available in header files