[Delegate] Support composite of lowered sub modules of the same backend (#59921)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/59921
Test Plan: Imported from OSS
Reviewed By: raziel
Differential Revision: D29091143
Pulled By: iseeyuan
fbshipit-source-id: 9ffcd18681917ece8ec73a34866c53701bdee1bc
