runtime(vim): Update base-syntax, configurable comment string highlighting (#14931)

Allow highlighting of strings within comments to be disabled by setting
g:vimsyn_comment_strings to false.

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 5ad4d00..7208661 100644
--- a/runtime/syntax/vim.vim
+++ b/runtime/syntax/vim.vim
@@ -408,7 +408,9 @@
 
 " Lower Priority Comments: after some vim commands... {{{2
 " =======================
-syn region	vimCommentString	contained oneline start='\S\s\+"'ms=e end='"'
+if get(g:, "vimsyn_comment_strings", 1)
+  syn region	vimCommentString	contained oneline start='\S\s\+"'ms=e end='"'
+endif
 
 if s:vim9script
   syn match	vimComment	excludenl +\s"[^\-:.%#=*].*$+lc=1	contains=@vimCommentGroup,vimCommentString contained