Gin ignores #description_display

Problem/Motivation

As I understand it, if the #description_display property is set on a form element, it should control where the help text (description) is rendered in the form display. Gin appears to ignore the setting.

Steps to reproduce

Create a node field (type of field doesn't matter), and in hook_form_alter or similar, set #description_display to 'before', which is not the default. Save and view the form: help text appears after the field widget rather than before it.

Proposed resolution

If #description_display is set, render the form field in the corresponding location relative to the field widget ('before', 'after' or 'invisible').