task: #3568491 Remove IE comment from FormBuilder

      // a response header.

      $element['#attached']['drupalSettings']['ajaxTrustedUrl'][$element['#action']] = TRUE;

      // If a form contains a single textfield, and the ENTER key is pressed

      // within it, Internet Explorer submits the form with no POST data

      // identifying any submit button. Other browsers submit POST data as

      // though the user clicked the first button. Therefore, to be as

      // consistent as we can be across browsers, if no 'triggering_element' has

      // been identified yet, default it to the first button.

      // A form submission can contain no data identifying a submit button,

      // for example when a form is submitted via GET, or when the ENTER key

      // is pressed within a single textfield. If no triggering element has

      // been identified, default it to the first button to keep form

      // processing consistent with submissions that include button data.

      $buttons = $form_state->getButtons();

      if (!$form_state->isProgrammed() && !$form_state->getTriggeringElement() && !empty($buttons)) {

        $form_state->setTriggeringElement($buttons[0]);