Demonstrate and fix [ 783882 ] os.lstat crashes with Unicode filename.

Will also check in on the 2.3 branch.
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 43af766..b8bda3b 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -4607,7 +4607,7 @@
 	return posix_do_stat(self, args, "et:lstat", lstat, NULL, NULL);
 #else /* !HAVE_LSTAT */
 #ifdef MS_WINDOWS
-	return posix_do_stat(self, args, "et:lstat", STAT, "u:lstat", _wstati64);
+	return posix_do_stat(self, args, "et:lstat", STAT, "U:lstat", _wstati64);
 #else
 	return posix_do_stat(self, args, "et:lstat", STAT, NULL, NULL);
 #endif