patch 8.0.0237: when 'wildoptions' is "tagfile" completion may not work

Problem:    When setting wildoptions=tagfile the completion context is not set
            correctly. (desjardins)
Solution:   Check for EXPAND_TAGS_LISTFILES. (Christian Brabandt, closes #1399)
diff --git a/src/ex_getln.c b/src/ex_getln.c
index 7de7246..4365100 100644
--- a/src/ex_getln.c
+++ b/src/ex_getln.c
@@ -4366,7 +4366,9 @@
 		|| context == EXPAND_OWNSYNTAX
 		|| context == EXPAND_FILETYPE
 		|| context == EXPAND_PACKADD
-		|| (context == EXPAND_TAGS && fname[0] == '/'))
+		|| ((context == EXPAND_TAGS_LISTFILES
+			|| context == EXPAND_TAGS)
+		    && fname[0] == '/'))
 	    retval = vim_strnsave(fname, len);
 	else
 	{