[vst3sdk] New port for Steinberg Virtual Studio Technology 3 SDK

[JoergAtGithub]

• Changes comply with the maintainer guide.
• The name of the port matches an existing name for this component on https://repology.org/ if possible, and/or is strongly associated with that component on search engines.
• [n.a.] Optional dependencies are resolved in exactly one way. For example, if the component is built with CMake, all find_package calls are REQUIRED, are satisfied by vcpkg.json's declared dependencies, or disabled with CMAKE_DISABLE_FIND_PACKAGE_Xxx.
• The versioning scheme in vcpkg.json matches what upstream says.
• The license declaration in vcpkg.json matches what upstream says.
• The installed as the "copyright" file matches what upstream says.
• The source code of the component installed comes from an authoritative source.
• [n.a.] The generated "usage text" is accurate. See adding-usage for context.
• The version database is fixed by rerunning ./vcpkg x-add-version --all and committing the result.
• Only one version is in the new port's versions file.
• Only one version is added to each modified port's versions file.

[JoergAtGithub]

The optional GUI module https://github.com/steinbergmedia/vstgui is not added to this port, as it has own version numbering and release cycle.

I was not able to get the macOS builds working on CI and therefore disabled them. It seems that the projects CMake files require the GUI version of Xcode and do not work with the command line version.

[dg0yt]

Regarding osx:

• Not supported seems wrong, it is more a CI problem, i.e. a fail in the CI baseline.
• Did you try to set ENV{XCODE_VERSION} and ENV{SDKROOT}?
  (IDK why this project wants environment variables at this point.)
  https://github.com/steinbergmedia/vst3_cmake/blob/2022b265cdbcd90b37294d3fb397f9766dbe4c06/modules/SMTG_DetectPlatform.cmake#L48-L60

[JoergAtGithub]

I already tried to set ENV{XCODE_VERSION}, but this alone was not sufficient.

[dg0yt]

Taking another look, that cmake script doesn't look convincing at all.
They determine (cmake) XCODE_VERSION when ENV{XCODE_VERSION} isn't set.
They determine (cmake) CMAKE_OSX_SYSROOT when ENV{SDKROOT} isn't set.

The key question is if they really need the XCode generator or GUI at some point, or if they just didn't know how to to make their cmake build more flexible.

[dg0yt]

Why is it okay to suppress this check?

(Why doesn't it use vcpkg_check_linkage()?)

[JoergAtGithub]

I could not get it to work with vcpkg_check_linkage so I removed these triplets from the list of supported triplets by !staticcrt

[JonLiu1993]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[JonLiu1993]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[dg0yt]

Please format if/else like

if(...)
    if(...)
        a()
    else()
        b()
    endif()
endif()

[JonLiu1993]

@JoergAtGithub, could you please reply @dg0yt's review?

[JonLiu1993]

Tested features [hosting-examples,hosting-examples] successfully in the followng triplet:

• x86-windows
• x64-windows
• x64-windows-static

[vicroms]

Are these executables required for the proper function of the library? Executable files should be installed in tools\${PORT} rather than share\${PORT}