Ignore shadow warns in code from macro expansions

[lochetti]

This PR fixes #9757

I am in doubt if just looking for pat.span.from_expansion() would be sufficient instead of looking for both pat.span.desugaring_kind().is_some() or pat.span.from_expansion(). The tests (including the new one) passes if I leave only if pat.span.from_expansion(). Any feedbacks?

Also, this is my first PR here, sorry for anything and thanks for the patience!

changelog: [shadow_same, shadow_reuse, shadow_unrelated]: avoiding warns in macro-generated code

[rustbot]

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[dswij]

Thanks for the PR!

For checking if the span is from macros, from_expansion() works just fine. I'd guess that the idea behind ignoring any spans from desugar (through desugaring_kind().is_some()) is just to be safe - i.e., shadows in desugared code should not be linted.

I'd say that it makes sense and it's fine to leave the desugar check as it is for now.

[dswij]

@bors r+

[bors]

📌 Commit 628605e has been approved by dswij

It is now in the queue for this repository.

[bors]

⌛ Testing commit 628605e with merge 5161c4c...

[bors]

☀️ Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test
Approved by: dswij
Pushing 5161c4c to master...

[bors]

☀️ Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test
Approved by: dswij
Pushing 5161c4c to master...