[gtk/msvc.nounistd] testsuite/testutils.c: Fix build on Visual Studio

[Chun-wei Fan <fanchunwei src gnome org>]

commit d8e8b3c23507e997e32797e0ba3b85673881853a
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Fri Jan 29 17:52:54 2021 +0800

    testsuite/testutils.c: Fix build on Visual Studio
    
    Visual Studio does not come with unistd.h, but Windows do have write() and
    close() in io.h, so include io.h instead of unistd.h on Windows.
    
    For MinGW, unistd.h in turn includes io.h.

 testsuite/testutils.c | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/testsuite/testutils.c b/testsuite/testutils.c
index 3d537e80dc..29df624cd9 100644
--- a/testsuite/testutils.c
+++ b/testsuite/testutils.c
@@ -19,7 +19,13 @@
 
 #include <glib.h>
 #include <glib/gstdio.h>
+
+#ifdef G_OS_WIN32
+#include <io.h>
+#else
 #include <unistd.h>
+#endif
+
 #include "testsuite/testutils.h"
 
 char *