[Dist Autograd][Better Engineering] Enhanced Error Reporting in Dist Autograd/RPC (#34179)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/34179
Fixes: https://github.com/pytorch/pytorch/issues/27644
Test Plan: Asserted `test_backward_autograd_engine_error` throws an exception with node information.
Differential Revision: D20238150
fbshipit-source-id: a49b279b77416a7e0e09043aa44ed616023d8e70
