Arm backend: Tag control flow submodules in partitioner

[Erik-Lundell]

Control flow operators are implemented with get_attr/ placeholders nodes pointing to submodules in the graph_module. To know if we can handle such an operators, we need to figure out whether we can partition all of the submodule the operator points to. We can do this simply by applying the partition logic we already have to submodules. This has the added benefit that we will partition parts of submodules into normal partitions, even if we can't partition the full submodule.

cc @freddan80 @per @zingo @oscarandersson8218 @digantdesai

[pytorch-bot]

🔗 Helpful Links

🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/executorch/15364

• 📄 Preview Python docs built from this PR

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

❌ 8 New Failures, 3 Unrelated Failures

As of commit c67e327 with merge base f7ca57e ():

NEW FAILURES - The following jobs have failed:

• pull / test-samsung-models-linux / linux-job (gh)
  RuntimeError: Command docker exec -t e41cfdaecddabc927e38ef576c5f4ecdad6b47e833dd1a1227656955f6788fc3 /exec failed with exit code 1
• pull / unittest-nxp-neutron / linux-job (gh)
  RuntimeError: Command docker exec -t d0adde3ea0fe1c5c50ea99079f5c3573c56499b67561e974f8b727eeffaa2bf6 /exec failed with exit code 1
• Test CUDA Builds / export-gemma3-cuda-non-quantized / linux-job (gh)
  RuntimeError: Command docker exec -t f0e11ef345b759700b897fc277e52fa477209ca8a427b9df1ec5efae25c98345 /exec failed with exit code 2
• Test CUDA Builds / export-gemma3-cuda-quantized-int4-tile-packed / linux-job (gh)
  RuntimeError: Command docker exec -t 0eb1b8f714663e7d429c332dfa9d67a0b4a140a74135ba8343b5c8eb42523601 /exec failed with exit code 2
• Test CUDA Builds / export-voxtral-cuda-non-quantized / linux-job (gh)
  RuntimeError: Command docker exec -t 1d2b3b777ffd201b4402bfc75969ff0d960353838565578283e77b0a244ff7c8 /exec failed with exit code 2
• Test CUDA Builds / export-voxtral-cuda-quantized-int4-tile-packed / linux-job (gh)
  RuntimeError: Command docker exec -t c05bcd98f5414ced1a68b24ad577397e02aeeb3de5557b5447e260560ab32e25 /exec failed with exit code 2
• Test CUDA Builds / export-voxtral-cuda-quantized-int4-weight-only / linux-job (gh)
  RuntimeError: Command docker exec -t d7895c578fe856c29166b85f73af4c4f92b8644c9502d34e43a595db9c7a9b29 /exec failed with exit code 2
• Test Metal Backend / export-voxtral-metal-artifact / macos-job (gh)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 2

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

• pull / unittest / linux / linux-job (gh) (detected as infra flaky with no log or failing log classifier)
• trunk / unittest-release / linux / linux-job (gh) (detected as infra flaky with no log or failing log classifier)

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 / linux / linux-job (gh) (trunk failure)

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

[Sebastian-Larsson]

Unrelated CI failures