Revert "Eliminate redundant NCHW↔NHWC permute_copy and NHWC-safe view_copy transposes in ToTosaMemoryFormatPass"

[Copilot]

Reverts #18314.

Summary

Reverts the NHWC-safe reshape detection and redundant permute_copy elimination introduced in #18314 (ToTosaMemoryFormatPass).

Test plan

Full revert of #18314 — no new logic introduced. Relevant tests:

pytest backends/arm/test/passes/test_to_tosa_memory_format.py
pytest backends/arm/test/ -v

These require the Arm/TOSA toolchain and cannot run in the automation environment.

Original prompt

Create a revert pull request for merged PR #18314 in repository pytorch/executorch.

Requirements:

1. Create a new branch off the default branch (main unless repo indicates otherwise).
2. Revert the merge commit(s) introduced by PR Eliminate redundant NCHW↔NHWC permute_copy and NHWC-safe view_copy transposes in ToTosaMemoryFormatPass (#18314) #18314 ("Eliminate redundant NCHW↔NHWC permute_copy and NHWC-safe view_copy transposes in ToTosaMemoryFormatPass"). Use git revert -m 1 <merge_sha>-equivalent semantics if it was merged via a merge commit; otherwise revert the relevant commits.
3. Ensure the revert builds/tests as per repo conventions:
   • Run the existing CI-relevant unit tests or minimal test suite if available in repo documentation.
   • If running tests is not possible in the automation environment, add a note in the PR description explaining what should be run.
4. PR title should be: "Revert "Eliminate redundant NCHW↔NHWC permute_copy and NHWC-safe view_copy transposes in ToTosaMemoryFormatPass""
5. PR description should include:
   • Link to PR Eliminate redundant NCHW↔NHWC permute_copy and NHWC-safe view_copy transposes in ToTosaMemoryFormatPass (#18314) #18314
   • Brief explanation that this PR reverts Eliminate redundant NCHW↔NHWC permute_copy and NHWC-safe view_copy transposes in ToTosaMemoryFormatPass (#18314) #18314
   • Any conflicts resolved or follow-up actions needed.

Acceptance criteria:

• The revert PR cleanly applies to the base branch and restores behavior prior to Eliminate redundant NCHW↔NHWC permute_copy and NHWC-safe view_copy transposes in ToTosaMemoryFormatPass (#18314) #18314.
• No unrelated formatting or refactoring changes.

The following is the prior conversation context from the user's chat exploration (may be truncated):

User: can you create a revert PR

Assistant: I’m waiting for you to accept the pending action request; once you do, I can proceed to create the revert pull request for #18314.

This pull request was created from Copilot chat.

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[pytorch-bot]

🔗 Helpful Links

🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/executorch/18555

• 📄 Preview Python docs built from this PR

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❌ 1 New Failure, 1 Cancelled Job, 2 Unrelated Failures

As of commit 109ac08 with merge base 502d2de ():

NEW FAILURE - The following job has failed:

• Lint / lintrunner-mypy (gh)
  >>> Lint for backends/arm/test/models/stable_diffusion/stable_diffusion_module_test_configs.py:

CANCELLED JOB - The following job was cancelled. Please retry:

• pull / unittest / macos / macos-job (gh)
  ##[error]The operation was canceled.

BROKEN TRUNK - The following jobs failed but were present on the merge base:

👉 Rebase onto the `viable/strict` branch to avoid these failures

• pull / unittest / windows / windows-job (gh) (trunk failure)
  ##[error]The operation was canceled.
• pull / unittest-editable / windows / windows-job (gh) (trunk failure)
  ##[error]The operation was canceled.

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