[LT] Support Tensor.is_alias_of
Summary:
Tensor.is_alias_of relies on Storage to perform. However, LTCTensorImpl was
not implemented with that in mind. This commit adds a fake storage to LazyTensor
as a marker to mark LazyTensors that point to the same storage. The reason
why it's not done at LTCTensorImpl is that LazyTensor maintains the view ops/alias
logic in LazyTensor class instead of relying on TensorImpl to do the check.
Test Plan:
./build/bin/test_lazy --gtest_filter=LazyOpsTest.IsAliasOf
Pull Request resolved: https://github.com/pytorch/pytorch/pull/75246
Approved by: https://github.com/bdhirsh
