Add pthread_main_np to FreeBSD-like and _lwp_self to NetBSD

[murarth]

No description provided.

[rust-highfive]

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

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[gnzlbg]

cc @asomers @bors r=asomers

[bors]

📌 Commit 36a92d5 has been approved by asomers

[bors]

⌛ Testing commit 36a92d5 with merge ff63cb5...

[bors]

☀️ Test successful - checks-cirrus-freebsd-10, checks-cirrus-freebsd-11, checks-cirrus-freebsd-12, status-azure
Approved by: asomers
Pushing ff63cb5 to master...

[asomers]

Not that there's anything wrong with this PR, but why did you tell bors that I approved it?

[gnzlbg]

I'm on holidays and I screwed it up. I wanted to delegate approving this PR to you so that you could approve it and tell bors to merge it, but instead of delegate=X I wrote r=X and apparently r=X is valid syntax that approves a PR in the name of somebody else =/ Sorry.