Restrict ADL for reference_wrapper and thread

[frederick-vs-ja]

This PR is unblocking two libcxx tests.

• std/thread/thread.threads/thread.thread.class/thread.thread.constr/robust_against_adl.pass.cpp
• std/utilities/function.objects/refwrap/refwrap.invoke/robust_against_adl.pass.cpp

Driven-by changes:

• <filesystem>: path's comparison operators are IF-NDR #2358 is fixed, but the related libcxx test still fails because it requires path's iterator to satisfy bidirectional_iterator. The explanation should be changed.
• Referenced number to the Working Draft in <type_traits> and <thread> are updated to WG21-N4917 with section numbers added.
• Other ADL-related failures get analyzed.

[strega-nil-ms]

Marking decision needed, as we need to discuss the underlying issue #140 this week at the STL maintainers' meeting.

[StephanTLavavej]

Removing decision needed (as we've decided in #140), and this PR doesn't actually involve qualifying _Ugly names.

[frederick-vs-ja]

Removing decision needed (as we've decided in #140), and this PR doesn't actually involve qualifying _Ugly names.

Oh, I'm sorry for doing too much in one commit.😹 This PR does _STD-qualify _Refwrap_ctor_fun (only this _Ugly name).

[strega-nil-ms]

This looks reasonable to me! Thanks!

[StephanTLavavej]

Thanks - I've pushed small changes to fix citations, clarify a comment, and remove unnecessary parens. FYI @strega-nil-ms (as you previously approved) and @CaseyCarter (if you want to double-check the citation that you added in 2019).

✅ No modules impact.

[CaseyCarter]

I'm not enthusiastic about section numbers in our working draft citations - they're just noise - but it's not worth the effort to pull them out at this point.

[frederick-vs-ja]

I'm not enthusiastic about section numbers in our working draft citations - they're just noise - but it's not worth the effort to pull them out at this point.

I can go with removal of section numbers. Should we make an issue to track this?

[StephanTLavavej]

I'm mirroring this to the MSVC-internal repo - please notify me if any further changes are pushed.

[StephanTLavavej]

Thanks for investigating and fixing these libcxx test failures! 🚀 😻 📉

[StephanTLavavej]

@frederick-vs-ja We already had #182, so I updated that issue to mention that section numbers should be dropped.