[NFC] Add logging

[AaronStGeorge]

While working on a recent change I found the logging here very convenient, maybe it should be permanent?

[ftynse]

I was adding a breakpoint at this place to inspect the program, so looks helpful.

[zjgarvey]

I do think this might be a bit aggressive logging for other use-cases of aot.export (e.g. full models with thousands of lines of IR), but I'm fine with this.

If we want to move away from using aot.export/CompiledModule in BOO, I'm fine with that too. We are essentially only using the torch.export, fx_importer, and CustomOpExpansionPass pieces of this tech, so it might just make more sense to just use those directly and do the logging in BOO.