Arm backend: Add TOSA PAD dialect op

[oscarandersson8218]

Adds new TOSA dialect op for PAD. aten.constant_pad_nd nodes are replaced by tosa.PAD in RewritePadPass. op_constant_pad_nd node visitor is replaced by a simpler node vistior for tosa.PAD.

cc @digantdesai @SS-JIA @freddan80 @per @zingo @mansnils @Sebastian-Larsson @robell

[pytorch-bot]

🔗 Helpful Links

🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/executorch/17940

• 📄 Preview Python docs built from this PR

Note: Links to docs will display an error until the docs builds have been completed.

❌ 4 New Failures, 3 Unrelated Failures

As of commit 679c32e with merge base 6b5283c ():

NEW FAILURES - The following jobs have failed:

• pull / test-samsung-models-linux / linux-job (gh)
  RuntimeError: Command docker exec -t 148f8fc9b12da9a7e98b4c63e064633e0282b6bc43ea81904b115468e33b392e /exec failed with exit code 1
• pull / test-samsung-quantmodels-linux / linux-job (gh)
  RuntimeError: Command docker exec -t a2d9b09f9793288ce0e56e909d3320b7f0b2abeb4000da1adfc8890c06e5f81e /exec failed with exit code 1
• trunk / test-arm-cortex-m-size-test (bare_metal) / linux-job (gh)
  RuntimeError: Command docker exec -t ee39fb56400ac1c675c36022bf47a359136b17a222fae735dcf0cf22b930bda4 /exec failed with exit code 1
• trunk / test-arm-cortex-m-size-test (zephyr-preset) / linux-job (gh)
  RuntimeError: Command docker exec -t 6e8a4979f666e381b96194d322800521e5a7329adca06e4bcd8bb288b33d6623 /exec failed with exit code 1

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 / macos / macos-job (gh) (trunk failure)
  AttributeError: '_OpNamespace' 'mkldnn' object has no attribute '_is_mkldnn_acl_supported'
• pull / unittest-editable / macos / macos-job (gh) (trunk failure)
  AttributeError: '_OpNamespace' 'mkldnn' object has no attribute '_is_mkldnn_acl_supported'
• trunk / unittest-release / macos / macos-job (gh) (trunk failure)
  AttributeError: '_OpNamespace' 'mkldnn' object has no attribute '_is_mkldnn_acl_supported'

This comment was automatically generated by Dr. CI and updates every 15 minutes.

[zingo]

Hi @SS-JIA this adds a file but I also spot srcs = glob(["op_*.py", "ops_*.py"]), so I think it should be fine.

[oscarandersson8218]

cortex_m_size_test failures are not introduced by this patch. Probably introduced by #17326.