Clears the lastcommentmodified cached value when a comment status is changed.

Deletes the lastcommentmodified cache key when a comment enters or leaves
‘approved’ status.

function _clear_modified_cache_on_transition_comment_status( $new_status, $old_status ) {
	if ( 'approved' === $new_status || 'approved' === $old_status ) {
		$data = array();
		foreach ( array( 'server', 'gmt', 'blog' ) as $timezone ) {
			$data[] = "lastcommentmodified:$timezone";
		}
		wp_cache_delete_multiple( $data, 'timeinfo' );
	}
}