[1/n][multi-tower] add partition info in predictor construction (#34175)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/34175
to incorporate PartitionInfo added in D20015493
Test Plan: unit tests
Reviewed By: yinghai
Differential Revision: D20133759
fbshipit-source-id: 130db2d80bca3c05a7ec91292159f857046718e0
