"QueryException: node_type not found" when deleting field from comment

Steps to reproduce:

1. Install 8.x with the standard profile.
2. Go to admin/structure/types/manage/article/comment/fields.
3. Delete the comment body field. The field is deleted, but you will see the exception:
   

   Drupal\Core\Entity\Query\QueryException: node_type not found in Drupal\field_sql_storage\Entity\Tables->ensureEntityTable() (line 100 of /.../core/modules/field/modules/field_sql_storage/lib/Drupal/field_sql_storage/Entity/Tables.php
   

The bug also occurs with field instances on taxonomy vocabularies, but not with fields on node types. ManageFieldsTest does not catch it because it uses node rather than a test entity. I'm working on converting that test to expose the bug.