The register-protocol optimization is not enabled when the interpreter is enabled

[rolfbjarne]

See:

https://github.com/xamarin/xamarin-macios/blob/f29834a751b20e2b26f348219f1fc9b6df19ea4b/tools/common/Optimizations.cs#L268

The register-protocol optimization is used to determine whether static interface constructors from the managed-static registrar are trimmed away or not:

https://github.com/xamarin/xamarin-macios/blob/f29834a751b20e2b26f348219f1fc9b6df19ea4b/tools/linker/CoreOptimizeGeneratedCode.cs#L1365-L1377

and this is required to get smaller apps + not reference frameworks unnecessarily (see #21002).

The current workaround is to add this to the csproj:

<PropertyGroup>
	<MtouchExtraArgs>--optimize:register-protocols</MtouchExtraArgs>
</PropertyGroup>

[rolfbjarne]

Potential fix:

The register-protocol optimization is required to be able to remove the static interface constructors (because otherwise the removed static constructors are needed at runtime), so the only other option is to apply the register-protocol optimization even when the interpreter is enabled. At the moment I can't see any reason why this shouldn't work.