Rename define to JACK_ON_WINDOWS

[pljones]

Short description of changes
Renames a define.

CHANGELOG: Rename existing define to JACK_ON_WINDOWS

Context: Fixes an issue?
Renames a define. Makes it consistent with the CONFIG option.

Does this change need documentation? What needs to be documented and how?
No.

Status of this Pull Request
Ready.

What is missing until this pull request can be merged?
Ready.

Checklist

• I've verified that this Pull Request follows the general code principles
• I tested my code and it does what I want
• My code follows the style guide
• I waited some time after this Pull Request was opened and all GitHub checks completed without errors.
• I've filled all the content above

[pljones]

Should line 104 stop the build? It's not going to work, after all...

[hoffie]

I'd say yes.

[pljones]

Mm, I'll do that in another PR.

[pljones]

If I remember...

[ann0see]

Just open an issue to let you remember :-)

[hoffie]

Yep, that's certainly better than before.

In general, I was thinking whether linux/ should be renamed to jack/ (or at least parts of it? haven't checked). It's really strange to add linux/ on Windows or Mac builds.

I'm also wondering whether JACK_REPLACES_ASIO/JACK_ON_WINDOWS/JACK_ON_MAC could go away at some point (after all, there's WITH_JACK and there are defines for the actual platform as well, so I don't see the point of having one extra define for JACK on each platform).

All of that exceeds the scope of this PR though, so just adding this here as a comment.

cc @henkdegroot who last touched the JACK autobuild logic at least (although not directly related to the actual code parts).

[hoffie]

I'd say yes.

[ann0see]

Merged since it's a trivial change.