[D7] entity_get_controller and null $class problem

This is an attempt to reopen issue #45111 for drupal 7 again. It appears the issue was fixed for 8, but the fix was never backported. I'm running into the issue on an open atrium install, and so far it seems like my best option may be to reinstall open atrium to get the issue resolved. The code for `entity_get_controller` is identical on the latest open atrium version and the latest drupal 7 core.

Steps to reproduce:

install open atrium
`drush en oa_workbench`

It appears that this causes drupal to believe there should be a WorkbenchModerationProfileController, that doesn't exist. which causes the following error:

PHP Fatal error:  Class 'WorkbenchModerationProfileController' not found in /path/to/drupal/includes/common.inc on line 8038
Drush command terminated abnormally due to an unrecoverable error.                                           [error]
Error: Class 'WorkbenchModerationProfileController' not found in
/path/to/drupal/includes/common.inc, line 8038

trying to get a controller that doesn't exist seems to pretty much break drupal. I caused it by trying to install a module and now can't disable the module or anything. I don't know how to fix it beyond starting again from scratch, and large segments of the admin interface no longer show up. I think this probably qualifies for the Critical priority.