patch 8.1.0164: luaeval('vim.buffer().name') returns an error

Problem:    luaeval('vim.buffer().name') returns an error.
Solution:   Return an empty string. (Dominique Pelle, closes #3167)

src/version.c

@@ -789,6 +789,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    164,
 /**/
     163,
 /**/