[Release/2.0.0] Reduce desktop targeted reference assemblies in 2.0 release

[ericstj]

See https://github.com/dotnet/corefx/issues/23505.

The use of reference assemblies in 2.0 for desktop-targeted packages and netstandard support targets has resulted in a number of tooling issues.

To help relieve these, we can dial back the number of reference assemblies we use.

1. Don't use reference assemblies at all for the support package / targets.
   • [release/2.0.0] Remove reference assemblies from NetFx netstandard support package corefx#23711
   • Will need to be ingested into SDK
2. For packages which have reference facades which are full facades, don't set the reference assembly bit.
   • Remove reference assembly attribute from partial ref facade when it is a full facade buildtools#1663
   • Needs to be ported to release/2.0.0
   • The following packages will benefit from this:
     • Microsoft.Win32.Registry
     • System.CodeDom
     • System.ComponentModel.Annotations
     • System.Configuration.ConfigurationManager
     • System.Data.SqlClient
     • System.IO.Packaging
     • System.IO.Ports
     • System.Security.AccessControl
     • System.Security.Cryptography.Cng
       • for all but net461 see below
     • System.Security.Cryptography.Pkcs
     • System.Security.Cryptography.ProtectedData
     • System.Security.Cryptography.Xml
     • System.Security.Principal.Windows
     • System.ServiceProcess.ServiceController
     • System.Threading.Tasks.Extensions
3. For the remaining packages, consider excluding the desktop reference and instead using the implementation assembly as the reference (as we did in 1.x). These are the packages we shipped in 2.0 that contained reference assemblies with typedefs for desktop:
   • System.Numerics.Vectors
   • System.IO.FileSystem.AccessControl
   • System.IO.Pipes.AccessControl
   • System.Reflection.TypeExtensions
   • System.Security.Cryptography.Cng
     • only on net461 as a result of the netstandard remapping. Fix here is to drop those types from the reference for the netfx build.
   • System.Threading.AccessControl

1 is a must-fix for 2.0. For 2 and 3 we'd need to ship the individual packages and for that I'd like a shiproom read.

[Petermarcu]

dotnet/corefx#23711

[danmoseley]

@weshaggard is there any work left here for 2.0.2?

[ericstj]

We did 1, we were blocked on doing 2 & 3 due to buildtools being in limbo. That's since been fixed. I think we can decide if we want to do 2 & 3 and ship them at some future date (not necessarily in 2.0.2).

[alexdrl]

We're having an issue with a Xamarin project, which as we added System.IO.Packaging 4.4.1 nuget package dependency, the reference is resolved as the ref/netstandard1.3 DLL, a reference assembly. It seems that because of that, the Xamarin app fails to start because this DLL does not get packaged, and so the app fails to start with this common xamarin error https://forums.xamarin.com/discussion/63584/android-could-not-load-assembly-xxx-during-startup-registration

Would be this resolved with this change?

[ericstj]

@alexdrl that is different. All Xamarin frameworks have their own TFM which differs from desktop.

2 has already happened in 2.1 branch.

I'll open a new issue to track 3.