[executorch] Fix remove_clone_ops to prevent output aliasing

[GregoryComer]

Stack from ghstack (oldest at bottom):

• [executorch] Update XNNPACK backend to use input_spec metadata + support HOPs #18147
• [executorch] Update delegation and partitioning to use input_spec metadata #18146
• [executorch] Rewrite remove_unused_parameters_pass for HOP support #18145
• [executorch] Add propagate_input_spec pass and while_loop HOP support #18144
• -> [executorch] Fix remove_clone_ops to prevent output aliasing #18143

Add a _would_cause_output_aliasing check to RemoveCloneOpsTransform.
When preserve_input_output_copies is set, we now also preserve clones
where removing them would cause the same source node to appear multiple
times in the output tuple, which is invalid.

This shows up with HOPs and can cause lowering failures in some circumstances.

Differential Revision: D95876983

[pytorch-bot]

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❌ 10 New Failures

As of commit 4601e90 with merge base 48bd687 ():

NEW FAILURES - The following jobs have failed:

• Build Presets / windows (pybind) / build (gh)
  The process 'C:\Program Files\Git\cmd\git.exe' failed with exit code 1
• Build Presets / windows (windows) / build (gh)
  The process 'C:\Program Files\Git\cmd\git.exe' failed with exit code 1
• pull / unittest / windows / windows-job (gh)
  The process 'C:\Program Files\Git\cmd\git.exe' failed with exit code 1
• pull / unittest-editable / windows / windows-job (gh)
  The process 'C:\Program Files\Git\cmd\git.exe' failed with exit code 1
• Test CUDA Windows Export and E2E / test-model-cuda-windows-e2e (mistralai, Voxtral-Mini-3B-2507, non-quantized) / windows-job (gh)
  The process 'C:\Program Files\Git\cmd\git.exe' failed with exit code 1
• Test CUDA Windows Export and E2E / test-model-cuda-windows-e2e (mistralai, Voxtral-Mini-3B-2507, quantized-int4-weight-only) / windows-job (gh)
  The process 'C:\Program Files\Git\cmd\git.exe' failed with exit code 1
• Test CUDA Windows Export and E2E / test-model-cuda-windows-e2e (mistralai, Voxtral-Mini-4B-Realtime-2602, quantized-int4-tile-packed) / windows-job (gh)
  The process 'C:\Program Files\Git\cmd\git.exe' failed with exit code 1
• Test CUDA Windows Export and E2E / test-model-cuda-windows-e2e (nvidia, diar_streaming_sortformer_4spk-v2, non-quantized) / windows-job (gh)
  The process 'C:\Program Files\Git\cmd\git.exe' failed with exit code 1
• Test CUDA Windows Export and E2E / test-model-cuda-windows-e2e (nvidia, parakeet-tdt, non-quantized) / windows-job (gh)
  The process 'C:\Program Files\Git\cmd\git.exe' failed with exit code 1
• Test CUDA Windows Export and E2E / test-model-cuda-windows-e2e (nvidia, parakeet-tdt, quantized-int4-weight-only) / windows-job (gh)
  The process 'C:\Program Files\Git\cmd\git.exe' failed with exit code 1

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