Header changes so it will compile on VS

kernel/driver.cc

@@ -27,11 +27,14 @@
 
 #include <stdio.h>
 #include <string.h>
-#include <unistd.h>
-#include <libgen.h>
 #include <limits.h>
 #include <errno.h>
 
+#ifndef _WIN32
+#  include <unistd.h>
+#endif
+
+
 USING_YOSYS_NAMESPACE
 
 int main(int argc, char **argv)