[option_option]: Fix duplicate diagnostics

[cookie-s]

Relates to #12379

This option_option lint change skips checks against tys inside field_defs defined by external macro to prevent duplicate diagnostics to the same span ty by multiple Struct definitions.

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changelog: [option_option]: Fix duplicate diagnostics

[rustbot]

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[cookie-s]

The test failed because of #[derive(Serialize, Deserialize)] to struct Foo. There may be somewhere else where the in_external_macro guard can be added?

[llogiq]

Yeah, those expansion contexts are sometimes weird. Perhaps the struct was marked but not the fields or something like this.

[cookie-s]

I just added in_external_macro guard into check_field_def to make the test pass. If it's sufficient, I'd like this PR to be merged.

[llogiq]

That raises the question whether to lint this in macros at all. If yes, then I'll gladly merge this. Otherwise we should use span.from_expansion() instead.

[cookie-s]

@llogiq Thank you. That makes sense. I think it's better to skip all macros. I read this page too and updated to from_expansion.

[llogiq]

Thank you for improving this lint!

@bors r+

[bors]

📌 Commit 9408c59 has been approved by llogiq

It is now in the queue for this repository.

[bors]

⌛ Testing commit 9408c59 with merge d202eb6...

[bors]

☀️ Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test
Approved by: llogiq
Pushing d202eb6 to master...