Support symbolic for conv_tbc (#58359) (#58692)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/58692
This is a fix for exporting fairseq models, see:
```python
model = torch.hub.load(github, 'conv.wmt14.en-fr', tokenizer='moses', bpe='subword_nmt')
model = torch.hub.load(github, 'conv.wmt17.en-de', tokenizer='moses', bpe='subword_nmt')
```
With this fix, and comment out model script one line `GradMultiply`, these two models can be exported successfully with perf met.
The original PR https://github.com/pytorch/pytorch/pull/57708 has merging issue, use this one instead.
Test Plan: Imported from OSS
Reviewed By: driazati
Differential Revision: D28714809
Pulled By: SplitInfinity
fbshipit-source-id: 71c2de6cec7ee05af68560996acf47d97af46fb2
Co-authored-by: David <jiafa@microsoft.com>
