vim-patch:8.2.1754: completion with spell checking not tested (#12992)

vim-patch:8.2.1754: completion with spell checking not tested

Problem:    Completion with spell checking not tested.
Solution:   Add a test case. (Dominique Pellé, closes vim/vim#7024)
8c7ad3631a

Cherry-pick GetMessages() from patch 8.2.0666.
Comment out the code that checks for "Messages maintainer:" line
because Neovim's ":messages" command does not output it
and patches for the "methods" feature (ie. foo->bar) are not ported yet.

https://github.com/neovim/neovim/pull/5160

src/nvim/testdir/shared.vim

@@ -329,3 +329,17 @@ func RunVimPiped(before, after, arguments, pipecmd)
   endif
   return 1
 endfunc
+
+" Get all messages but drop the maintainer entry.
+func GetMessages()
+  redir => result
+  redraw | messages
+  redir END
+  let msg_list = split(result, "\n")
+  " if msg_list->len() > 0 && msg_list[0] =~ 'Messages maintainer:'
+  "   return msg_list[1:]
+  " endif
+  return msg_list
+endfunc
+
+" vim: shiftwidth=2 sts=2 expandtab