[msbuild] Fix the FindAotCompiler task for .NET 7.

[rolfbjarne]

Compute the .NET version to use when generating the project file to compute
the AOT compiler.

Also include a way to always force the computation, even on macOS (this eases
testing).

Fixes https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1597624.

[rolfbjarne]

/sudo backport release/7.0.1xx-rc1

[vs-mobiletools-engineering-service2]

Backport Job to branch release/7.0.1xx-rc1 Created! The magic is happening here

[vs-mobiletools-engineering-service2]

Hooray! Backport succeeded! Please see https://devdiv.visualstudio.com/DevDiv/_build/results?buildId=6601073 for more details.

[rolfbjarne]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[vs-mobiletools-engineering-service2]

📚 [PR Build] Artifacts 📚

Packages generated

View packages

• Microsoft.iOS.Bundle.15.4.1023-ci.pr.gh15759.pkg
• Microsoft.iOS.Ref.15.4.1023-ci.pr.gh15759.nupkg
• Microsoft.iOS.Runtime.ios-arm.15.4.1023-ci.pr.gh15759.nupkg
• Microsoft.iOS.Runtime.ios-arm64.15.4.1023-ci.pr.gh15759.nupkg
• Microsoft.iOS.Runtime.iossimulator-arm64.15.4.1023-ci.pr.gh15759.nupkg
• Microsoft.iOS.Runtime.iossimulator-x64.15.4.1023-ci.pr.gh15759.nupkg
• Microsoft.iOS.Runtime.iossimulator-x86.15.4.1023-ci.pr.gh15759.nupkg
• Microsoft.iOS.Sdk.15.4.1023-ci.pr.gh15759.nupkg
• Microsoft.iOS.Templates.15.4.1023-ci.pr.gh15759.nupkg
• Microsoft.iOS.Windows.Sdk.15.4.1023-ci.pr.gh15759.nupkg
• Microsoft.MacCatalyst.Bundle.15.4.1023-ci.pr.gh15759.pkg
• Microsoft.MacCatalyst.Ref.15.4.1023-ci.pr.gh15759.nupkg
• Microsoft.MacCatalyst.Runtime.maccatalyst-arm64.15.4.1023-ci.pr.gh15759.nupkg
• Microsoft.MacCatalyst.Runtime.maccatalyst-x64.15.4.1023-ci.pr.gh15759.nupkg
• Microsoft.MacCatalyst.Sdk.15.4.1023-ci.pr.gh15759.nupkg
• Microsoft.MacCatalyst.Templates.15.4.1023-ci.pr.gh15759.nupkg
• Microsoft.macOS.Bundle.12.3.1023-ci.pr.gh15759.pkg
• Microsoft.macOS.Ref.12.3.1023-ci.pr.gh15759.nupkg
• Microsoft.macOS.Runtime.osx-arm64.12.3.1023-ci.pr.gh15759.nupkg
• Microsoft.macOS.Runtime.osx-x64.12.3.1023-ci.pr.gh15759.nupkg
• Microsoft.macOS.Sdk.12.3.1023-ci.pr.gh15759.nupkg
• Microsoft.macOS.Templates.12.3.1023-ci.pr.gh15759.nupkg
• Microsoft.NET.Sdk.iOS.Manifest-7.0.100-rc.2.15.4.1023-ci.pr.gh15759.nupkg
• Microsoft.NET.Sdk.MacCatalyst.Manifest-7.0.100-rc.2.15.4.1023-ci.pr.gh15759.nupkg
• Microsoft.NET.Sdk.macOS.Manifest-7.0.100-rc.2.12.3.1023-ci.pr.gh15759.nupkg
• Microsoft.NET.Sdk.tvOS.Manifest-7.0.100-rc.2.15.4.1023-ci.pr.gh15759.nupkg
• Microsoft.NET.Workload.iOS.15.4.1023-ci.pr.gh15759.msi
• Microsoft.tvOS.Bundle.15.4.1023-ci.pr.gh15759.pkg
• Microsoft.tvOS.Ref.15.4.1023-ci.pr.gh15759.nupkg
• Microsoft.tvOS.Runtime.tvos-arm64.15.4.1023-ci.pr.gh15759.nupkg
• Microsoft.tvOS.Runtime.tvossimulator-arm64.15.4.1023-ci.pr.gh15759.nupkg
• Microsoft.tvOS.Runtime.tvossimulator-x64.15.4.1023-ci.pr.gh15759.nupkg
• Microsoft.tvOS.Sdk.15.4.1023-ci.pr.gh15759.nupkg
• Microsoft.tvOS.Templates.15.4.1023-ci.pr.gh15759.nupkg
• xamarin.ios-15.13.0.219.pkg
• xamarin.mac-8.13.0.219.pkg

Pipeline on Agent XAMMINI-008.Monterey
Hash: 48b078eebfcbe71223603391f9ce0b29aa592e97 [PR build]

[vs-mobiletools-engineering-service2]

💻 [PR Build] Tests on macOS Mac Catalina (10.15) passed 💻

✅ All tests on macOS Mac Catalina (10.15) passed.

Pipeline on Agent
Hash: 48b078eebfcbe71223603391f9ce0b29aa592e97 [PR build]

[vs-mobiletools-engineering-service2]

❌ [PR Build] Tests on macOS M1 - Mac Big Sur (11.5) failed ❌

Failed tests are:

• introspection
• xammac_tests
• monotouch-test

Pipeline on Agent
Hash: 48b078eebfcbe71223603391f9ce0b29aa592e97 [PR build]

[vs-mobiletools-engineering-service2]

✅ API diff for current PR / commit

Legacy Xamarin (No breaking changes)

• iOS (no change detected)
• tvOS (no change detected)
• watchOS (no change detected)
• macOS (no change detected)

.NET (No breaking changes)

• iOS: vsdrops gist (No breaking changes)
• tvOS: vsdrops gist (No breaking changes)
• MacCatalyst: vsdrops gist (No breaking changes)
• macOS: vsdrops gist (No breaking changes)

✅ API diff vs stable

Legacy Xamarin (No breaking changes)

• iOS: vsdrops gist (No breaking changes)
• tvOS: vsdrops gist (No breaking changes)
• watchOS: vsdrops gist (No breaking changes)
• macOS: vsdrops gist (No breaking changes)

.NET (No breaking changes)

• iOS: vsdrops gist (No breaking changes)
• tvOS: vsdrops gist (No breaking changes)
• MacCatalyst: vsdrops gist (No breaking changes)
• macOS: vsdrops gist (No breaking changes)
• Microsoft.iOS vs Microsoft.MacCatalyst: vsdrops gist

Legacy Xamarin (stable) vs .NET

• iOS: vsdrops gist
• tvOS: vsdrops gist
• macOS: vsdrops gist

✅ Generator diff

Generator diff is empty

Pipeline on Agent
Hash: 48b078eebfcbe71223603391f9ce0b29aa592e97 [PR build]

[vs-mobiletools-engineering-service2]

🚀 [CI Build] Test results 🚀

Test results

✅ All tests passed on VSTS: simulator tests.

🎉 All 223 tests passed 🎉

Tests counts

✅ 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 12 tests passed. Html Report (VSDrops) Download
✅ monotouch: All 23 tests passed. Html Report (VSDrops) Download
✅ msbuild: All 2 tests passed. Html Report (VSDrops) Download
✅ mtouch: All 1 tests passed. Html Report (VSDrops) Download
✅ xammac: All 3 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: [PR build]