patch 8.2.0988: getting directory contents is always case sorted

Problem:    Getting directory contents is always case sorted.
Solution:   Add sort options and v:collate. (Christian Brabandt, closes #6229)
diff --git a/src/config.h.in b/src/config.h.in
index 7055b6f..b114480 100644
--- a/src/config.h.in
+++ b/src/config.h.in
@@ -198,6 +198,7 @@
 #undef HAVE_SIGVEC
 #undef HAVE_SMACK
 #undef HAVE_STRCASECMP
+#undef HAVE_STRCOLL
 #undef HAVE_STRERROR
 #undef HAVE_STRFTIME
 #undef HAVE_STRICMP