Handle rustc_on_unimplemented in duplicated_attributes

[Nilstrieb]

#[rustc_on_unimplemented(
    on(
        _Self = "&str",
        label = "`a"
    ),
    on(
        _Self = "alloc::string::String",
        label = "a"
    ),
)]

The lint treats this as a repetition because rustc_on_unimplemented::on::label appears twice, but that's ok.

Fixes #12619

changelog: [duplicated_attributes]: fix handling of rustc_on_unimplemented

[rustbot]

r? @Jarcho

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[Nilstrieb]

Oops, that's what I get for throwing something up quickly before going to bed. Will fix (or someone else can fix it for me if you want to :D).

[bors]

☔ The latest upstream changes (presumably #12646) made this pull request unmergeable. Please resolve the merge conflicts.

[Nilstrieb]

r? xFrednet

[xFrednet]

Meow Meow, looks good to me! =^.^=

[xFrednet]

In code's domain where errors hide,
Two cats, sleek and full of pride,
They prowled through lint, keen and bright,
Their gaze fixed on bugs in the night.

"Duplicated attributes," they mew,
A bug they sought to construe,
Unstable feature, a lurking snare,
In rustc_on_unimplemented's lair.

With paws deft, they traced the line,
Unraveling errors, oh so fine,
Their purrs like whispers, soft and sweet,
Guiding devs to a bug's defeat.

So here's to cats, both wise and keen,
Who conquer bugs in code's machine,
Their legacy, a lint refined,
In their honor, let us r+.

[bors]

📌 Commit b10be16 has been approved by xFrednet

It is now in the queue for this repository.

[bors]

⌛ Testing commit b10be16 with merge 412b691...

[Nilstrieb]

meow :3

[bors]

☀️ Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test
Approved by: xFrednet
Pushing 412b691 to master...