Arm backend: Add support for asan in executor_runner

[perheld]

A lightweight AddressSanitizer runtime tailored for the ExecuTorch bare metal examples. The goal is to provide basic memory safety diagnostics while keeping the runtime self-contained.

This uses the kernel asan so it is not full asan.

Signed-off-by: per.held@arm.com
Change-Id: I7ca5a6d39450b13ed461f0d1b91e1f17ab69a42e

cc @freddan80 @per @zingo @oscarandersson8218 @digantdesai

[pytorch-bot]

🔗 Helpful Links

🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/executorch/16009

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✅ You can merge normally! (3 Unrelated Failures)

As of commit 81bcc21 with merge base a93f59e ():

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

• pull / test-models-linux (llama3_2_vision_encoder, portable, linux.4xlarge.memory) / linux-job (gh) (detected as infra flaky with no log or failing log classifier)
• pull / test-models-linux (phi_4_mini, portable, linux.4xlarge.memory) / 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

• Apple / build-demo-ios / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/runner/work/_temp/exec_script failed with exit code 74

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