Corecct ProcessInfo.operationSystemVersion on Windows

[yamoridon]

At Windows 8.1, Microsoft changed the default behavior of
GetVersionEx not to return actual version number for preventing
compatibility isseus. I think it's better to use the product version
retrived from kernel32.dll as an alternative as Microsoft described in
a document:
https://docs.microsoft.com/en-us/windows/desktop/SysInfo/getting-the-system-version

[jakepetroules]

Please don't do this -- RtlGetVersion is a much more direct approach.

[compnerd]

The usage here is not for compatibility but rather reporting purposes. I agree with @jakepetroules - we should just resort to RtlGetVersion

[yamoridon]

If my understanding is correct, we can't use that approach. RtlGetVersion is a kernel mode function, so application programs can't use it.

[compnerd]

@yamoridon - no your understanding is not correct. The RtlFunctions are implemented in the kernel, but you can still use them in usermode. It just is a slightly roundabout way - you need to use GetProcAddress. If you want, I can make the change - its pretty easy.

[yamoridon]

@compnerd It's interesting. I try it. I think I can do it. Thank you!

[yamoridon]

Thank you for advice. How about this? Too long line?

[compnerd]

Minor naming things, but looks good otherwise!

[compnerd]

@swift-ci please test

[compnerd]

Can you also please squash the changes?

[yamoridon]

Does it mean following?

1. Close this PR.
2. Make a new branch.
3. Make changes on this PR as one commit on the new branch.
4. Make a new PR

[compnerd]

You can use git rebase -i to squash all the commits into a single commit and force push to the existing branch :-).

[yamoridon]

Seems to have succeeded. Thank you for your kind support!

[compnerd]

@swift-ci please test

[compnerd]

I think that this improves the Windows status quo, so I'm going to go ahead and merge this. If @millenomi has additional suggestions, they can be handled in a follow up.