[net8.0] [dotnet] Add support for multi-targeting.

[rolfbjarne]

[net8.0] [dotnet] Add support for multi-targeting.

Multi targetting is described here:
https://github.com/xamarin/xamarin-macios/blob/main/docs/multi-target-framework.md

This PR implements support for:

• Building using the first .NET 7 packages we shipped.
• Building using the last .NET 7 packages we've shipped.

In both cases by specifying the OS version in the target framework.

Additionally adding support for any other API/OS version is trivial: it's just
a matter of listing the corresponding versions in a few files (this is
particularly interesting to add support for preview versions).

It does so by:

• Renaming the ref, sdk and runtime packs to contain the target framework and
  the target platfrom version, so the packages will now be named:

  • iOS

    • Microsoft.iOS.Sdk.net8.0_16.4
    • Microsoft.iOS.Ref.net8.0_16.4
    • Microsoft.iOS.Runtime.ios-arm64.net8.0_16.4
    • Microsoft.iOS.Runtime.iossimulator-arm64.net8.0_16.4
    • Microsoft.iOS.Runtime.iossimulator-x64.net8.0_16.4

  • tvOS

    • Microsoft.tvOS.Sdk.net8.0_16.4
    • Microsoft.tvOS.Ref.net8.0_16.4
    • Microsoft.tvOS.Runtime.ios-arm64.net8.0_16.4
    • Microsoft.tvOS.Runtime.iossimulator-arm64.net8.0_16.4
    • Microsoft.tvOS.Runtime.iossimulator-x64.net8.0_16.4

  • Mac Catalyst

    • Microsoft.MacCatalyst.Sdk.net8.0_16.4
    • Microsoft.MacCatalyst.Ref.net8.0_16.4
    • Microsoft.MacCatalyst.Runtime.maccatalyst-x64.net8.0_16.4
    • Microsoft.MacCatalyst.Runtime.maccatalyst-arm64.net8.0_16.4

  • macOS

    • Microsoft.macOS.Sdk.net8.0_13.3
    • Microsoft.macOS.Ref.net8.0_13.3
    • Microsoft.macOS.Runtime.osx-x64.net8.0_13.3
    • Microsoft.macOS.Runtime.osx-arm64.net8.0_13.3

• Updating the WorkloadManifest.json and WorkloadManifest.targets files to
  load the correct packs according to the TargetFramework in the developer's
  project.

• We're also now giving a better error message for invalid/unsupported/eol'ed
  target frameworks. Fixes Improve error message when targeting net6.0-ios and net6.0-macos from net 8 #18790.

• Add a few tests.

Fixes:

• Improve error message when targeting net6.0-ios and net6.0-macos from net 8 #18790.
• [net7] Creating a cross-targeted net7.0-ios + net6.0-ios packages forces consumers to build with net7 workloads dotnet/sdk#30103.
• Try to show a helpful error message with an invalid OS version in the TFM #16802.

Contributes towards:

• Figure out how to publish Xcode preview packages #18343.

[vs-mobiletools-engineering-service2]

🔥 Failed to compare API and create generator diff 🔥

Failed to update apidiff references

Pipeline on Agent
Hash: eaa69e79b766b3c360a0cd6be216c77ea42f36eb [PR build]

[vs-mobiletools-engineering-service2]

📚 [PR Build] Artifacts 📚

Packages generated

View packages

• xamarin.ios-16.5.0.838.pkg
• xamarin.mac-9.4.0.838.pkg

Pipeline on Agent
Hash: [PR build]

[vs-mobiletools-engineering-service2]

💻 [CI Build] Windows Integration Tests passed 💻

✅ All Windows Integration Tests passed.

Pipeline on Agent
Hash: eaa69e79b766b3c360a0cd6be216c77ea42f36eb [PR build]

[vs-mobiletools-engineering-service2]

💻 [PR Build] Tests on macOS M1 - Mac Ventura (13.0) passed 💻

✅ All tests on macOS M1 - Mac Ventura (13.0) passed.

Pipeline on Agent
Hash: [PR build]

[vs-mobiletools-engineering-service2]

💻 [PR Build] Tests on macOS M1 - Mac Big Sur (11.5) passed 💻

✅ All tests on macOS M1 - Mac Big Sur (11.5) passed.

Pipeline on Agent
Hash: [PR build]

[dalexsoto]

👍

[vs-mobiletools-engineering-service2]

🔥 [CI Build] Test results 🔥

Test results

❌ Tests failed on VSTS: simulator tests

0 tests crashed, 3 tests failed, 230 tests passed.

Failures

❌ xammac tests

3 tests failed, 0 tests passed.

• xammac tests/Mac Modern/Debug: Failed (Test run failed.
  Tests run: 2846 Passed: 2751 Inconclusive: 8 Failed: 2 Ignored: 93)
• xammac tests/Mac Modern/Release: Failed (Test run failed.
  Tests run: 2843 Passed: 2748 Inconclusive: 8 Failed: 1 Ignored: 94)
• xammac tests/Mac Modern/Release (all optimizations): Failed (Test run failed.
  Tests run: 2843 Passed: 2749 Inconclusive: 8 Failed: 2 Ignored: 92)

Html Report (VSDrops) Download

Successes

✅ bcl: All 69 tests passed. Html Report (VSDrops) Download
✅ cecil: All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests: All 1 tests passed. Html Report (VSDrops) Download
✅ fsharp: All 7 tests passed. Html Report (VSDrops) Download
✅ framework: All 8 tests passed. Html Report (VSDrops) Download
✅ generator: All 2 tests passed. Html Report (VSDrops) Download
✅ interdependent_binding_projects: All 7 tests passed. Html Report (VSDrops) Download
✅ install_source: All 1 tests passed. Html Report (VSDrops) Download
✅ introspection: All 8 tests passed. Html Report (VSDrops) Download
✅ linker: All 65 tests passed. Html Report (VSDrops) Download
✅ mac_binding_project: All 1 tests passed. Html Report (VSDrops) Download
✅ mmp: All 2 tests passed. Html Report (VSDrops) Download
✅ mononative: All 6 tests passed. Html Report (VSDrops) Download
✅ monotouch: All 39 tests passed. Html Report (VSDrops) Download
✅ msbuild: All 2 tests passed. Html Report (VSDrops) Download
✅ mtouch: All 1 tests passed. Html Report (VSDrops) Download
✅ xcframework: All 8 tests passed. Html Report (VSDrops) Download
✅ xtro: All 2 tests passed. Html Report (VSDrops) Download

Pipeline on Agent
Hash: eaa69e79b766b3c360a0cd6be216c77ea42f36eb [PR build]

[rolfbjarne]

Test failures are unrelated (https://github.com/xamarin/maccore/issues/2630).