Revert "inductor: remove conv_bn folding from pre_grad pass (#106686)"
This reverts commit 2a16457976c884b9cd1f196120529464c880e7ba.
Reverted https://github.com/pytorch/pytorch/pull/106686 on behalf of https://github.com/kit1980 due to Depends on reverted https://github.com/pytorch/pytorch/pull/106576 ([comment](https://github.com/pytorch/pytorch/pull/106686#issuecomment-1670753365))
