patch 8.2.3268: cannot use a block with :autocmd like with :command

Problem:    Cannot use a block with :autocmd like with :command.
Solution:   Add support for a {} block after :autocmd. (closes #8620)
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index c72e9c1..f2ff787 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -5203,7 +5203,7 @@
 	      _(e_command_not_allowed_from_vimrc_in_current_dir_or_tag_search);
     }
     else if (eap->cmdidx == CMD_autocmd)
-	do_autocmd(eap->arg, eap->forceit);
+	do_autocmd(eap, eap->arg, eap->forceit);
     else
 	do_augroup(eap->arg, eap->forceit);
 }