Remove SWFUpload,

- Refactor swfupload.js to output a simple upload form, and handlers.js.
- Delete the SWFUpload plugins directory and swfupload.swf.
- Remove flash cookies "hack" from async-upload.php.

See #41752.
Built from https://develop.svn.wordpress.org/trunk@41554


git-svn-id: http://core.svn.wordpress.org/trunk@41387 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/includes/update-core.php

@@ -716,6 +716,8 @@ $_old_files = array(
 // 4.9
 'wp-includes/js/plupload/plupload.flash.swf',
 'wp-includes/js/plupload/plupload.silverlight.xap',
+'wp-includes/js/swfupload/plugins',
+'wp-includes/js/swfupload/swfupload.swf',
 );
 
 /**