Arm backend: Promote InsertDataLayoutCastsPass up pass list

[tom-arm]

• Move above Aten -> TOSA transforms to ensure dtypes are valid

Change-Id: I021289f51f75e1a303050d0ffcf3b939f67ee88f

cc @digantdesai @freddan80 @per @zingo @oscarandersson8218 @mansnils @Sebastian-Larsson @robell

[pytorch-bot]

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❌ 1 New Failure, 1 Cancelled Job, 10 Unrelated Failures

As of commit 09c0efb with merge base 1debeb6 ():

NEW FAILURE - The following job has failed:

• pull / android / run-emulator (gh)
  The process '/usr/local/lib/android/sdk/platform-tools/adb' failed with exit code 224

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

• trunk / test-models-macos-cpu (ic4, xnnpack-quantization-delegation) / macos-job (gh)
  ##[error]The operation was canceled.

FLAKY - The following job failed but was likely due to flakiness present on trunk:

• trunk / test-qnn-model (fp32, dl3) / linux-job (gh) (matched linux rule in flaky-rules.json)
  The process '/usr/bin/git' failed with exit code 1

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

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

• pull / unittest / macos / macos-job (gh) (trunk failure)
  ##[error]The operation was canceled.
• pull / unittest / windows / windows-job (gh) (trunk failure)
  ##[error]The operation was canceled.
• pull / unittest-editable / macos / macos-job (gh) (trunk failure)
  ##[error]The operation was canceled.
• pull / unittest-editable / windows / windows-job (gh) (trunk failure)
  ##[error]The operation was canceled.
• Test CoreML Backend / test-coreml / test-backend-macos (coreml, models) / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 1
• Test CoreML Backend / test-coreml / test-backend-macos (coreml, operators) / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 1
• trunk / test-models-windows (mobilebert, portable) / windows-job (gh) (trunk failure)
  ##[error]The operation was canceled.
• trunk / unittest-release / macos / macos-job (gh) (trunk failure)
  ##[error]The operation was canceled.
• trunk / unittest-release / windows / windows-job (gh) (trunk failure)
  ##[error]The operation was canceled.

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[Copilot]

Pull request overview

This PR adjusts the Arm backend TOSA lowering pipeline ordering so InsertDataLayoutCastsPass runs before the Aten→TOSA rewrite passes, ensuring unsupported dtypes for data-layout ops are cast to a spec-supported dtype prior to transformation.

Changes:

• Moved InsertDataLayoutCastsPass() from the postprocessing/cleanup block to the end of the pre Aten→TOSA transformation pass block.
• As a result, dtype-correction casts are inserted while the graph still contains the targeted Aten ops (e.g., cat, view_copy, permute_copy, slice_copy, etc.).

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