Make threadpoolsize(), threadpooltids(), and ngcthreads() public

[JamesWrigley]

threadpoolsize() and ngcthreads() were already in the docs anyway, and threadpooltids() is useful for checking which threads belong to a pool.

[JamesWrigley]

(bump)

[gbaraldi]

threadpoolsize anad ngcthreads are fine but threadpooltids is an internal that we don't want the user to see or care about ;)

[JamesWrigley]

But I need to care about it 😅 For context, this is the usecase that motivated the PR: https://github.com/Gnimuc/CImGui.jl/blob/7c315112271b61d59c35873a2f1691021fb40198/ext/GlfwOpenGLBackend.jl#L177

That function allows pinning a task on a specific thread or in a given threadpool, which is sometimes necessary for libuv/GLFW reasons, but to do that I do need a valid thread ID. I could try recomputing the valid thread IDs but that's not completely trivial going from the definition so I feel that it would better if this was public.

[vchuravy]

Making something public is a commitment to an API, which we are not ready to make. It's often fine to access internals, but you need to be aware of the fact that you are doing so (and you don't get to complain when a future Julia version changes things on you).

So threadpooltids not being public is very much intended.

[JamesWrigley]

Ok, fair enough 👍 I rebased the branch and removed threadpooltids() from the commit.

[JamesWrigley]

Bump, AFAICS the test failures are unrelated.

[IanButterworth]

Note that they are already in the manual, so this is just a bugfix really.