Add --explain flag to bench (#89316)
TORCHDYNAMO_DYNAMIC_SHAPES=1 AOT_DYNAMIC_SHAPES=1 time python benchmarks/dynamo/torchbench.py --accuracy --explain --backend aot_eager --train --only BERT_pytorch
Dynamo produced 76 graphs with 75 graph break and 198 ops
Pull Request resolved: https://github.com/pytorch/pytorch/pull/89316
Approved by: https://github.com/ezyang
