$wp_rewrite->add_rule( "{$archive_slug}/?$", "index.php?post_type=$post_type", 'top' );
if ( $args->rewrite['feeds'] && $wp_rewrite->feeds ) {
$feeds = '(' . trim( implode( '|', $wp_rewrite->feeds ) ) . ')';
$wp_rewrite->add_rule( "{$archive_slug}/?$", "index.php?post_type=$post_type", 'top' );
if ( $args->rewrite['feeds'] && $wp_rewrite->feeds ) {
$feeds = '(' . trim( implode( '|', $wp_rewrite->feeds ) ) . ')';