runtime: set 'cpoptions' for line-continuation in various runtime files

closes: #17121

Signed-off-by: Eisuke Kawashima <e-kwsm@users.noreply.github.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/syntax/pacmanlog.vim b/runtime/syntax/pacmanlog.vim
index 98abd58..798b48f 100644
--- a/runtime/syntax/pacmanlog.vim
+++ b/runtime/syntax/pacmanlog.vim
@@ -2,11 +2,15 @@
 " Language: pacman.log
 " Maintainer: Ronan Pigott <ronan@rjp.ie>
 " Last Change: 2023 Dec 04
+" 2025 Apr 16 by Vim Project (set 'cpoptions' for line continuation, #17121)
 
 if exists("b:current_syntax")
   finish
 endif
 
+let s:cpo_save = &cpo
+set cpo&vim
+
 syn sync maxlines=1
 syn region pacmanlogMsg start='\S' end='$' keepend contains=pacmanlogTransaction,pacmanlogALPMMsg
 syn region pacmanlogTag start='\['hs=s+1 end='\]'he=e-1 keepend nextgroup=pacmanlogMsg
@@ -39,3 +43,6 @@
 hi def link pacmanlogPackageVersion Comment
 
 let b:current_syntax = "pacmanlog"
+
+let &cpo = s:cpo_save
+unlet s:cpo_save