[StaticRuntime] Add out variant for reshape and flatten

[hlu1]

Summary:

• Add out variant for reshape and flatten. reshape and flatten only create tensor views when it can. In cases where it can't, it does a copy. The out variant reuses the TensorImpl for both cases. The difference is that the TensorImpl is a view in the first case, but a normal TensorImpl in the second case.
• Create a separate registry for the view ops with out variants. Because Tensor views can't participate in memory reuse (memonger), we need to track these ops separately.
• The MemoryPlanner does not track the StorageImpl of tensor views because they don't own the storage, however, in cases where reshape does not create a view, the MemoryPlanner does manage the output tensor.

Reviewed By: ajyu

Differential Revision: D25992202

[facebook-github-bot]

💊 CI failures summary and remediations

As of commit 58af815 (more details on the Dr. CI page):

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• 1/2 failures possibly* introduced in this PR
  • 1/1 non-CircleCI failure(s)
• 1/2 broken upstream at merge base 2de4ecd on Jan 27 from 3:19pm to 5:24pm

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🚧 1 fixed upstream failure:

These were probably caused by upstream breakages that were already fixed.

Please rebase on the viable/strict branch (expand for instructions)

If your commit is older than viable/strict, run these commands:

git fetch https://github.com/pytorch/pytorch viable/strict
git rebase FETCH_HEAD

Check out the recency history of this "viable master" tracking branch.

• pytorch_linux_xenial_py3_6_gcc5_4_test on Jan 27 from 3:19pm to 5:24pm (2de4ecd - 1c8d11c)
  • 🔁 rerun

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Extra GitHub checks: 1 failed

• Failed: GitHub Actions - clang-tidy

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[facebook-github-bot]

This pull request was exported from Phabricator. Differential Revision: D25992202

[facebook-github-bot]

This pull request has been merged in d035d56.