patch 7.4.1980
Problem:    'errorformat' is parsed for every call to ":caddexpr".  Can't add
            to two location lists asynchronously.
Solution:   Keep the previously parsed data when appropriate. (mostly by
            Yegappan Lakshmanan)
diff --git a/src/version.c b/src/version.c
index 1e9672b..7c2abf6 100644
--- a/src/version.c
+++ b/src/version.c
@@ -759,6 +759,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1980,
+/**/
     1979,
 /**/
     1978,