gtk: Add show_menubar=on|off command line option.

The patch adds "show_menubar" command line option for GTK UI similar to
"show_tabs". This option allows to hide menu bar initially, it still can
be toggled by shortcut and other shortcuts still work.

Signed-off-by: Bryce Mills <brycemills@proton.me>
Acked-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <NWO_zx1CT5Aj9vAXsRlqBppXd63gcKwL9V1qM1Meh36M_9tCw-EsCnfpvONXhHjmtKIUoSuCy9OO6cHS7M8b0oHBOCZG6f1jZ4Q2tqgI2Qo=@proton.me>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
diff --git a/qemu-options.hx b/qemu-options.hx
index 95b998a..bb0979b 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -1969,6 +1969,7 @@
 #if defined(CONFIG_GTK)
     "-display gtk[,full-screen=on|off][,gl=on|off][,grab-on-hover=on|off]\n"
     "            [,show-tabs=on|off][,show-cursor=on|off][,window-close=on|off]\n"
+    "            [,show-menubar=on|off]\n"
 #endif
 #if defined(CONFIG_VNC)
     "-display vnc=<display>[,<optargs>]\n"
@@ -2061,6 +2062,8 @@
 
         ``window-close=on|off`` : Allow to quit qemu with window close button
 
+        ``show-menubar=on|off`` : Display the main window menubar, defaults to "on"
+
     ``curses[,charset=<encoding>]``
         Display video output via curses. For graphics device models
         which support a text mode, QEMU can display this output using a