Arm backend: Eliminate redundant NCHW↔NHWC permute_copy and NHWC-safe view_copy transposes in ToTosaMemoryFormatPass (#18167)

[3l1]

Summary:

Two optimizations in ToTosaMemoryFormatPass to reduce TOSA TRANSPOSE nodes:

1. NHWC-safe reshape detection: When a 4D→4D view_copy has monotonic
   shape_indices on the raw shapes and preserves the last dimension (NHWC
   channel), skip inserting input/output transposes. The view_copy can
   operate directly on NHWC data.

2. Redundant permute_copy elimination: Model-level permute_copy ops whose
   permutation matches channels_last_order (NCHW→NHWC) or its inverse
   (NHWC→NCHW) are redundant with the tosa_dim_order annotation that
   already handles format conversion. Replace them with view_copy (identity
   reshape) to avoid generating TOSA TRANSPOSE nodes.

Reviewed By: digantdesai

Differential Revision: D96432610

[pytorch-bot]

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❌ 8 New Failures, 2 Cancelled Jobs, 2 Pending, 3 Unrelated Failures

As of commit 79951e1 with merge base bb8318d ():

NEW FAILURES - The following jobs have failed:

• Apple / build-frameworks-ios / macos-job (gh)
• pull / unittest-arm-backend-with-no-deps (test_pytest_models_tosa) / linux-job (gh)
  RuntimeError: Command docker exec -t 2edc62075f47b0b6577bcb3b95f0f79f28e668570b4a106c2d9f0c4655aa4ff0 /exec failed with exit code 1
• pull / unittest-arm-backend-with-no-deps (test_pytest_ops_tosa) / linux-job (gh)
  RuntimeError: Command docker exec -t b7689fee051b15ebb57296d17b0f981eb6b4ab0f19b4a89eaa2df07758206b47 /exec failed with exit code 1
• trunk / test-arm-backend-ethos-u (test_pytest_models_ethos_u85) / linux-job (gh)
  RuntimeError: Command docker exec -t 21197facfa32253a2e5fa690ab367ae1c0b8d92f03d263da262f4af082c26708 /exec failed with exit code 1
• trunk / test-arm-backend-ethos-u (test_pytest_ops_ethos_u55) / linux-job (gh)
  RuntimeError: Command docker exec -t 510430e51eee8587ad6be8eb169ee12d034c81feb49414dca812bbfd6f5e777c /exec failed with exit code 1
• trunk / test-arm-backend-ethos-u (test_pytest_ops_ethos_u85) / linux-job (gh)
  RuntimeError: Command docker exec -t 83b19fa7433da73d892dfb7f1f9b03654e31ac587ddcf6ac16c8eec9862d7469 /exec failed with exit code 1
• trunk / test-arm-backend-ethos-u (test_smaller_stories_llama) / linux-job (gh)
  RuntimeError: Command docker exec -t 3c076023a2c61ca4190750980d897370a278b717eda0afdf04a555508592093d /exec failed with exit code 1
• trunk / test-arm-backend-vkml (test_pytest_ops_vkml) / linux-job (gh)
  RuntimeError: Command docker exec -t f0b8f562cbea8e6d0807ad6c11a6b8a9dab9b43368cce222ff30a4256aba5b56 /exec failed with exit code 1

CANCELLED JOBS - The following jobs were cancelled. Please retry:

• trunk / test-selective-build-macos (cmake) / macos-job (gh)
  ##[error]The operation was canceled.
• trunk / unittest-release / macos / macos-job (gh)
  ##[error]The operation was canceled.

FLAKY - The following jobs failed but were likely due to flakiness present on trunk:

• pull / unittest / windows / windows-job (gh) (matched win rule in flaky-rules.json)
  ##[error]The operation was canceled.
• trunk / unittest-release / windows / windows-job (gh) (matched win rule in flaky-rules.json)
  ##[error]The operation was canceled.

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

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

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

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[digantdesai]

Review automatically exported from Phabricator review in Meta.

[3l1]

Im investigating the failing tests...