cursor-renderer/native: Update HW state during frames

Before each frame is maybe redrawn, push any new cursor KMS state to the
pending update. It'll then either be posted during the next page flip,
or when the same frame finishes, in case nothing was redrawn.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1488>

src/backends/meta-monitor.c

@@ -1948,6 +1948,28 @@ meta_monitor_mode_foreach_output (MetaMonitor          *monitor,
   return TRUE;
 }
 
+MetaMonitorCrtcMode *
+meta_monitor_get_crtc_mode_for_output (MetaMonitor     *monitor,
+                                       MetaMonitorMode *mode,
+                                       MetaOutput      *output)
+{
+  MetaMonitorPrivate *monitor_priv =
+    meta_monitor_get_instance_private (monitor);
+  GList *l;
+  int i;
+
+  for (l = monitor_priv->outputs, i = 0; l; l = l->next, i++)
+    {
+      MetaMonitorCrtcMode *monitor_crtc_mode = &mode->crtc_modes[i];
+
+      if (monitor_crtc_mode->output == output)
+        return monitor_crtc_mode;
+    }
+
+  g_warn_if_reached ();
+  return NULL;
+}
+
 const char *
 meta_monitor_get_display_name (MetaMonitor *monitor)
 {