runtime(vim): Update base-syntax, allow parens in default arguments

Allow parentheses in default arguments specified in :def and :function
definitions.

fixes #16243
closes: #16269

Signed-off-by: Doug Kearns <dougkearns@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/syntax/vim.vim b/runtime/syntax/vim.vim
index bcd4124..d0295c3 100644
--- a/runtime/syntax/vim.vim
+++ b/runtime/syntax/vim.vim
@@ -2,7 +2,7 @@
 " Language:	   Vim script
 " Maintainer:	   Hirohito Higashi <h.east.727 ATMARK gmail.com>
 "	   Doug Kearns <dougkearns@gmail.com>
-" Last Change:	   2024 Dec 17
+" Last Change:	   2024 Dec 21
 " Former Maintainer: Charles E. Campbell
 
 " DO NOT CHANGE DIRECTLY.
@@ -354,8 +354,8 @@
 syn keyword	vimFuncKey	contained	fu[nction]
 syn keyword	vimDefKey	contained	def
 
-syn region	vimFuncParams	contained	matchgroup=Delimiter start="(" skip=+\n\s*\\\|\n\s*"\\ + end=")" skipwhite skipempty nextgroup=vimFuncBody,vimFuncComment,vimEndfunction,vimFuncMod,vim9CommentError	contains=vimFuncParam,@vimContinue
-syn region	vimDefParams	contained	matchgroup=Delimiter start="("		   end=")" skipwhite skipempty nextgroup=vimDefBody,vimDefComment,vimEnddef,vimReturnType,vimCommentError	contains=vimDefParam,vim9Comment,vimFuncParamEquals
+syn region	vimFuncParams	contained	matchgroup=Delimiter start="(" skip=+\n\s*\\\|\n\s*"\\ + end=")" skipwhite skipempty nextgroup=vimFuncBody,vimFuncComment,vimEndfunction,vimFuncMod,vim9CommentError	contains=vimFuncParam,vimOperParen,@vimContinue
+syn region	vimDefParams	contained	matchgroup=Delimiter start="("		   end=")" skipwhite skipempty nextgroup=vimDefBody,vimDefComment,vimEnddef,vimReturnType,vimCommentError	contains=vimDefParam,vim9Comment,vimFuncParamEquals,vimOperParen
 syn match	vimFuncParam	contained	"\<\h\w*\>\|\.\.\."	skipwhite nextgroup=vimFuncParamEquals
 syn match	vimDefParam	contained	"\<\h\w*\>"		skipwhite nextgroup=vimParamType,vimFuncParamEquals