COMMENT_FORM_BELOW and COMMENT_FORM_SEPARATE_PAGE moved to constants on CommentItem class

The constants COMMENT_FORM_BELOW and COMMENT_FORM_SEPARATE_PAGE were moved to the Drupal\comment\Plugin\Field\FieldType\CommentItem class as FORM_BELOW and FORM_SEPARATE_PAGE.

Drupal 7

function mymodule_some_function($form_location) {
  if ($form_location == COMMENT_FORM_BELOW) {
    // Do something.
  }
}

Drupal 8

use Drupal\comment\Plugin\Field\FieldType\CommentItem;

function mymodule_some_function($form_location) {
  if ($form_location == CommentItem::FORM_BELOW) {
    // Do something.
  }
}