patch 9.0.0310: output of :messages dissappears when cmdheight is zero

Problem:    Output of :messages dissappears when cmdheight is zero.
Solution:   Do not use the messages window for :messages.  Make Esc close the
            messages window.
diff --git a/src/message.c b/src/message.c
index 096f274..e4f8af1 100644
--- a/src/message.c
+++ b/src/message.c
@@ -1077,6 +1077,7 @@
     }
 
     msg_hist_off = TRUE;
+    dont_use_message_window();
 
     p = first_msg_hist;
     if (eap->addr_count != 0)
diff --git a/src/normal.c b/src/normal.c
index 6fcdaeb..12b611e 100644
--- a/src/normal.c
+++ b/src/normal.c
@@ -6820,7 +6820,14 @@
 	redraw_curbuf_later(UPD_INVERTED);
     }
     else if (no_reason)
-	vim_beep(BO_ESC);
+    {
+#ifdef HAS_MESSAGE_WINDOW
+	if (popup_message_win_visible())
+	    popup_hide_message_win();
+	else
+#endif
+	    vim_beep(BO_ESC);
+    }
     clearop(cap->oap);
 
     // A CTRL-C is often used at the start of a menu.  When 'insertmode' is
diff --git a/src/version.c b/src/version.c
index c69e46c..d8a6862 100644
--- a/src/version.c
+++ b/src/version.c
@@ -708,6 +708,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    310,
+/**/
     309,
 /**/
     308,