patch 8.0.0074
Problem:    Cannot make Vim fail on an internal error.
Solution:   Add IEMSG() and IEMSG2(). (Domenique Pelle)  Avoid reporting an
            internal error without mentioning where.
diff --git a/src/dict.c b/src/dict.c
index 136348b..07d1000 100644
--- a/src/dict.c
+++ b/src/dict.c
@@ -214,7 +214,7 @@
 
     hi = hash_find(&dict->dv_hashtab, item->di_key);
     if (HASHITEM_EMPTY(hi))
-	EMSG2(_(e_intern2), "dictitem_remove()");
+	internal_error("dictitem_remove()");
     else
 	hash_remove(&dict->dv_hashtab, hi);
     dictitem_free(item);