runtime(vim): accept dot in completionList for Vim9 syntax (#13832)
if you have autoloaded command complete function in vim9script, it shouldn't be highlighted as Error:
```
import autoload "share.vim"
command! -range=% -nargs=? -complete=custom,share.Complete Share share.Paste(<q-args>, <line1>, <line2>)
```
`share.Complete` is a valid complete function.
Signed-off-by: Maxim Kim <habamax@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/syntax/vim.vim b/runtime/syntax/vim.vim
index edfef43..165a809 100644
--- a/runtime/syntax/vim.vim
+++ b/runtime/syntax/vim.vim
@@ -316,7 +316,7 @@
syn keyword vimUserAttrbKey contained bar ban[g] cou[nt] ra[nge] com[plete] n[args] re[gister]
syn keyword vimUserAttrbCmplt contained augroup buffer behave color command compiler cscope dir environment event expression file file_in_path filetype function help highlight history locale mapping menu option packadd shellcmd sign syntax syntime tag tag_listfiles user var
syn keyword vimUserAttrbCmplt contained custom customlist nextgroup=vimUserAttrbCmpltFunc,vimUserCmdError
-syn match vimUserAttrbCmpltFunc contained ",\%([sS]:\|<[sS][iI][dD]>\)\=\%(\h\w*\%(#\h\w*\)\+\|\h\w*\)"hs=s+1 nextgroup=vimUserCmdError
+syn match vimUserAttrbCmpltFunc contained ",\%([sS]:\|<[sS][iI][dD]>\)\=\%(\h\w*\%([.#]\h\w*\)\+\|\h\w*\)"hs=s+1 nextgroup=vimUserCmdError
syn case match
syn match vimUserAttrbCmplt contained "custom,\u\w*"