[arc_with_non_send_sync] Improve suggested resolution

[m-rph]

Fixes: #11714

Improved the lint message for [arc_with_non_send_sync] to suggest using RC unless user needs an Arc, then suggests wrapping in a mutex, and then suggests implementing Sync and Send.

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changelog: [arc_with_non_send_sync]: Suggest RC over unsafe impl of Send and Sync

[rustbot]

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[blyxyas]

This is pretty much ready, just a little improvement that I think would improve readability.

[blyxyas]

LGTM, thanks! ❤️ Could you squash the 4 commits into a single one?

[m-rph]

Great! :D

I don't have write access so I can't squash-merge, and squash - (force) push would need another approval.

If that's fine I will get to it!

[blyxyas]

Yeah don't worry, use git rebase -i HEAD~4 (replace "pick" with "s" in those four commits), adjust the commit messages and just git push -f. Rebasing is the scenario where a force push would be accepted.

[m-rph]

Awesome, thanks Alejandra!

[blyxyas]

@bors r+

[bors]

📌 Commit 399fe32 has been approved by blyxyas

It is now in the queue for this repository.

[bors]

⌛ Testing commit 399fe32 with merge e16d42f...

[bors]

☀️ Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test
Approved by: blyxyas
Pushing e16d42f to master...