vim-patch:8.0.0208

Problem:    Internally used commands for CTRL-Z and mouse click end up in
            history. (Matthew Malcomson)
Solution:   Use do_cmdline_cmd() instead of stuffing them in the readahead
            buffer. (James McCoy, closes vim/vim#1395)

25b0e6b701

Closes #5966
Closes #5967

src/nvim/edit.c

@@ -800,7 +800,7 @@ static int insert_handle_key(InsertState *s)
     if (!p_im) {
       goto normalchar;                // insert CTRL-Z as normal char
     }
-    stuffReadbuff((char_u *)":st\r");
+    do_cmdline_cmd("stop");
     s->c = Ctrl_O;
   // FALLTHROUGH