So, I tried commenting out the error checking routine inside lib/auth/ldap.php, and yes it did allow me to log in after the upgrade. However, it allows me to log in with incorrect credentials now. For example, I use a correct user account name, but can enter any password I choose and it allows me to log in.
If I uncomment the error routine, and attempt to log in again, it simply reroutes me to a blank white screen. Have you encountered this before?