Fix Windows CI Failure

Author: Thirumalai-Shaktivel

src/lpython/utils.h

@@ -7,11 +7,14 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #ifndef _WIN32
-#include <unistd.h>
+    #include <unistd.h>
 #endif
 
 #ifdef _WIN32
-#define stat _stat
+    #define stat _stat
+    #if !defined S_ISDIR
+        #define S_ISDIR(m) (((m) & _S_IFDIR) == _S_IFDIR)
+    #endif
 #endif
 
 namespace LFortran {