xla

7d6a7234 - [DDP] Add a test case for XRT (#4014)

[DDP] Add a test case for XRT (#4014) Summary: This pull request extends the existing PJRT DDP correctness test to support XRT as well. Test Plan: MASTER_ADDR=localhost MASTER_PORT=6001 python test/test_ddp.py TestXrtDistributedDataParallel