Ampersand missing from referenced parameters

[flack]

This is a follow-up to phpDocumentor/phpDocumentor#1406.

With the following docblock:

/**
 * @param array $data The data.
 */
public function do_something(array &$data)

There is no ampersand rendered in the documentation. With the responsive-twig template, this works as expected, so it seems that this is a bug in the clean template

[samlev]

Also failing to render an ampersand in clean now, too.