consider aliased mappers in cycles also

consider aliased mappers in cycles also

Fixed endless loop which could occur when using "relationship to aliased
class" feature and also indicating a recursive eager loader such as
``lazy="selectinload"`` in the loader, in combination with another eager
loader on the opposite side. The check for cycles has been fixed to include
aliased class relationships.

Fixes: #9590
Change-Id: I8d340882f040ff9289c209bedd8fbdfd7186f944
(cherry picked from commit e79ab08165e01dc7af50fcffadb31468ace51b6c)