patch 8.0.1292: quick clicks in the WinBar start Visual mode

Problem:    Quick clicks in the WinBar start Visual mode.
Solution:   Use a double click in the WinBar like a normal click.
diff --git a/src/ui.c b/src/ui.c
index d7daf94..d370ad4 100644
--- a/src/ui.c
+++ b/src/ui.c
@@ -2653,6 +2653,21 @@
 	    return IN_STATUS_LINE;
 	if (on_sep_line)
 	    return IN_SEP_LINE;
+#ifdef FEAT_MENU
+	if (in_winbar)
+	{
+	    /* A quick second click may arrive as a double-click, but we use it
+	     * as a second click in the WinBar. */
+	    if ((mod_mask & MOD_MASK_MULTI_CLICK) && !(flags & MOUSE_RELEASED))
+	    {
+		wp = mouse_find_win(&row, &col);
+		if (wp == NULL)
+		    return IN_UNKNOWN;
+		winbar_click(wp, col);
+	    }
+	    return IN_OTHER_WIN | MOUSE_WINBAR;
+	}
+#endif
 	if (flags & MOUSE_MAY_STOP_VIS)
 	{
 	    end_visual_mode();