fixup! io: smooth out non-POSIX function usage across platforms

Author: widlarizer

kernel/gzip.cc

@@ -2,11 +2,17 @@
 #include "kernel/log.h"
 #include "kernel/gzip.h"
 #include <iostream>
-#include <dirent.h>
 #include <string>
 #include <cstdarg>
 #include <cstdio>
 
+#if !defined(WIN32)
+#include <dirent.h>
+#include <unistd.h>
+#else
+#include <io.h>
+#endif
+
 YOSYS_NAMESPACE_BEGIN
 
 #ifdef YOSYS_ENABLE_ZLIB