patch 8.2.3584: "verbose set efm" reports location of the :compiler command

Problem:    "verbose set efm" reports the location of the :compiler command.
            (Gary Johnson)
Solution:   Add the "-keepscript" argument to :command and use it when
            defining CompilerSet.
diff --git a/src/ex_cmds2.c b/src/ex_cmds2.c
index 15560d8..8e7da18 100644
--- a/src/ex_cmds2.c
+++ b/src/ex_cmds2.c
@@ -754,7 +754,7 @@
 		if (old_cur_comp != NULL)
 		    old_cur_comp = vim_strsave(old_cur_comp);
 		do_cmdline_cmd((char_u *)
-			      "command -nargs=* CompilerSet setlocal <args>");
+		   "command -nargs=* -keepscript CompilerSet setlocal <args>");
 	    }
 	    do_unlet((char_u *)"g:current_compiler", TRUE);
 	    do_unlet((char_u *)"b:current_compiler", TRUE);