fix export issue

[billmguo]

Summary:
Root cause: decompose_wrap_with_autocast.py:64 built the remap dict keyed by the parent graph's argument node names (n_args[i].name), but merge_decomposed_graph looks up entries by the decomposed submodule's placeholder names (decomposed_node.name). After 17 prior QNN passes transform the graph, argument nodes get renamed/replaced, causing the names to diverge. The placeholder 'permute_3' in the submodule no longer matches any key in remap.

Fix: Build remap by extracting placeholders from the decomposed submodule and mapping them positionally to n_args[5:], which is the correct correspondence regardless of node naming. This matches the pattern all other callers of merge_decomposed_graph use (hardcoded placeholder names from modules they control).

Differential Revision: D103306388

[pytorch-bot]

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❌ 1 New Failure, 2 Unrelated Failures

As of commit 37ee96a with merge base 2108986 ():

NEW FAILURE - The following job has failed:

• pull / android / run-emulator (gh)
  The process '/usr/local/lib/android/sdk/platform-tools/adb' failed with exit code 224

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

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[meta-codesync]

@billmguo has exported this pull request. If you are a Meta employee, you can view the originating Diff in D103306388.

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