Define IO_REPARSE_TAG_SYMLINK if its not defined by WinNT.h
diff --git a/src/win32/posix_w32.c b/src/win32/posix_w32.c
index fb82465..a74fcaa 100644
--- a/src/win32/posix_w32.c
+++ b/src/win32/posix_w32.c
@@ -19,6 +19,10 @@
# define FILE_NAME_NORMALIZED 0
#endif
+#ifndef IO_REPARSE_TAG_SYMLINK
+#define IO_REPARSE_TAG_SYMLINK (0xA000000CL)
+#endif
+
/* Options which we always provide to _wopen.
*
* _O_BINARY - Raw access; no translation of CR or LF characters