Fix static shape propagation in aten.as_strided

[raayandhar]

Intermediate view operations were not properly propagating static shapes. Thanks to Zach for pointing out how to fix this issue, see #4325 for more discussion. They key change is viewShapeInts[dim] = size to preserve the static shape.

I have kept the e2e Python tests for aten.unflatten and the MLIR tests for the TorchToLinalg conversion of unflatten as well, I think they may be useful for some more coverage that wasn't there before, but open to suggestions on whether or not to keep these.

[zjgarvey]

Thanks for the fix. I'd remove the unrelated tests (unflatten isn't actually related to the code change). Let me know when you'd like me to take another look and we can get it merged.

[raayandhar]

Thanks for the fix. I'd remove the unrelated tests (unflatten isn't actually related to the code change). Let me know when you'd like me to take another look and we can get it merged.

Thanks for the feedback - I think it should be good for a look now.

[raayandhar]

@zjgarvey now that we landed the fixes so that we don't get aten.as_strided in decompositions anymore, should we close this? But my understanding is that the OP still exists so it hasn't been fully deprecated yet...

[zjgarvey]

@raayandhar we should really emit a fatal error on seeing this op. There is no way we can support this.

[raayandhar]

@raayandhar we should really emit a fatal error on seeing this op. There is no way we can support this.

Sounds good, closing