[BUG] AOT compile fails for iOS MAUI

Describe the bug

I’m unable to build an AOT release build for iOS MAUI with ReactiveUI v17.1.17. Building with verbose gives me this

Failed to load method 0x6000472 from '[...]/obj/iPhone/Release/net6.0-ios/ios-arm64/linked/ReactiveUI.dll' due to Could not resolve signature of method ReactiveUI.ReactiveCollectionViewSource`1[TSource]:NumberOfSections.
Mono Ahead of Time compiler - compiling assembly [...]/obj/iPhone/Release/net6.0-ios/ios-arm64/linked/ReactiveUI.dll
Run with MONO_LOG_LEVEL=debug for more information.
AOTID 765DC80D-F50C-E335-7D3F-74B08B59D889
AOT of image [...]/obj/iPhone/Release/net6.0-ios/ios-arm64/linked/ReactiveUI.dll failed.
Could not load signature of ReactiveUI.ReactiveCollectionViewSource`1[TSource]:NumberOfSections due to: Could not resolve type with token 010000b4 from typeref (expected class 'System.nint' in assembly 'Xamarin.iOS, Version=0.0.0.0, Culture=neutral, PublicKeyToken=84e04ff9cfb79065') assembly:Xamarin.iOS, Version=0.0.0.0, Culture=neutral, PublicKeyToken=84e04ff9cfb79065 type:System.nint member:(null)

Steps To Reproduce

Not sure on a repro just yet, but it fails for me when doing the following build:

dotnet build MyApp -t:Build -c:Release -f:net6.0-ios -p:Platform=iPhone -p:RuntimeIdentifier=ios-arm64 \
    -p:BuildIpa=True -p:OutputPath='bin/Simulator/' -p:TreatWarningsAsErrors=True

Expected behaviour

AOT compile works

Environment

• OS: macOS
• Version 12.2
• Device: intel-chip macbook pro
• ReactiveUI Version: 17.7.17

Additional context

dotnet version: 6.0.200 (installed via daily https://aka.ms/dotnet/6.0.2xx/daily/dotnet-sdk-osx-x64.pkg) xcode version: 13.2.1 MAUI version: preview 12

I installed the MAUI workload like this

sudo dotnet workload install maui --from-rollback-file https://aka.ms/dotnet/maui/preview.12.json \
    --source https://aka.ms/dotnet6/nuget/index.json  --source https://api.nuget.org/v3/index.json