Add hacky example inputs to dynamo produced graph (#96561)
Executorch currently uses functorch.functionalize API, as a result we have to invoke make_fx twice (one for filtering out autograd related stuff (happens in torchdynamo.export(aten=True) and one for tracing the functionalized version of the graph). The previous PR changes the make_fx behaviour to pass in fake tensors used in dynamo. But as Executorch invokes the second make_fx directly, we need to have access to fake tensors that dynamo used. We cannot call torchdynamo.export again in the second round because we don't have a way to functionalize inside dynamo at the moment. Hence I added this attribute in dynamo for now. Once we move to AOTAutograd functionalization, we don't have to deal with this anymore and I will remove this.
Differential Revision: [D43994692](https://our.internmc.facebook.com/intern/diff/D43994692)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/96561
Approved by: https://github.com/zhxchen17, https://github.com/voznesenskym
