Stabilize slice_split_at_unchecked

[wutchzone]

Greetings!

I took the opportunity, and I tried to stabilize the slice_split_at_unchecked feature. I followed the guidelines, and I hope everything was done correctly :crossed_fingers: .

Closes #76014

[rustbot]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @m-ou-se (or someone else) soon.

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[wutchzone]

@rustbot modify labels: +T-libs-api

[bors]

:umbrella: The latest upstream changes (presumably #120676) made this pull request unmergeable. Please resolve the merge conflicts.

[m-ou-se]

This will need an FCP for stabilization. I have updated the tracking issue and nominated it for discussion.

[wutchzone]

@m-ou-se (my apologies for pinging :pray:) The FCP stabilized this, do you think we can progress on this one, or are there any blockers?

[m-ou-se]

Thanks for the reminder!

@bors r+ rollup

[bors]

:pushpin: Commit 67c03579bc45a280548499d37ba2db7ef2e9f6a3 has been approved by m-ou-se

It is now in the queue for this repository.