runtime: Remove more fallback :CompilerSet definitions from compiler plugins (#14413)

Continue with #14399

Signed-off-by: jiangyinzuo <jiangyinzuo@foxmail.com>
Signed-off-by: Doug Kearns <dougkearns@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/compiler/mcs.vim b/runtime/compiler/mcs.vim
index 4d94f47..0c265b3 100644
--- a/runtime/compiler/mcs.vim
+++ b/runtime/compiler/mcs.vim
@@ -3,7 +3,7 @@
 " Maintainer:   Jarek Sobiecki <harijari@go2.pl>
 " Contributors: Peter Collingbourne and Enno Nagel
 " Last Change:  2024 Mar 29
-"		2024 Apr 03 by The Vim Project (removed :CompilerSet definition)
+"               2024 Apr 05 by The Vim Project (removed :CompilerSet definition)
 
 if exists("current_compiler")
   finish
@@ -13,10 +13,6 @@
 let s:cpo_save = &cpo
 set cpo-=C
 
-if exists(":CompilerSet") != 2 " Older Vim always used :setlocal
-  command -nargs=* CompilerSet setlocal <args>
-endif
-
 CompilerSet makeprg=mcs
 CompilerSet errorformat=
          \%D%.%#Project\ \"%f/%[%^/\"]%#\"%.%#,