IL weaver for adding nullability annotations to .NET Framework, .NET Standard, and .NET Core reference assemblies.

This is the continuation of TunnelVisionLabs.ReferenceAssemblyAnnotator, published as ICSharpCode.ReferenceAssemblyAnnotator. To migrate, replace the package ID; the MSBuild properties and items are unchanged.

• Build: .NET SDK 8 or newer, or Visual Studio 2022 version 17.8 or newer.

• .NET Framework targets
  • mscorlib
  • System
  • System.Core
  • System.Data
  • System.Drawing
  • System.IO.Compression.FileSystem
  • System.Numerics
  • System.Runtime.Serialization
  • System.Xml
  • System.Xml.Linq
• .NET Standard targets
  • All assemblies which are defined by the .NET Standard
• .NET Core targets before 3.0
  • All reference assemblies defined by .NET Core

.NET Core 3.0 and newer are not annotated: their reference assemblies already carry nullable annotations. Don't add the Microsoft.NETCore.App.Ref PackageDownload for those target frameworks. The SDK may download that package itself, and a second download fails restore with NU1505. When multi-targeting, condition it, for example:

<!-- <TargetFrameworks>netstandard2.0;net10.0</TargetFrameworks> -->
<PackageDownload Include="Microsoft.NETCore.App.Ref" Version="[10.0.0]" Condition="'$(TargetFramework)' != 'net10.0'" />

<PropertyGroup>
  <!-- By default, the nullable attributes from dotnet/coreclr are included as source code with 'internal'
       accessibility. Uncomment to suppress this if the attributes are included from another source and/or
       are not needed. -->
  
  <!-- <GenerateNullableAttributes>false</GenerateNullableAttributes> -->
</PropertyGroup>

<ItemGroup>
  <PackageReference Include="ICSharpCode.ReferenceAssemblyAnnotator" Version="2.0.0-preview.*" PrivateAssets="all" />

  <!-- Specifies the version of Microsoft.NETCore.App.Ref to obtain nullability information from. -->
  <PackageDownload Include="Microsoft.NETCore.App.Ref" Version="[10.0.0]" />
</ItemGroup>

Minimal:

<ItemGroup>
  <PackageReference Include="ICSharpCode.ReferenceAssemblyAnnotator" Version="2.0.0-preview.*" PrivateAssets="all" />
  <PackageDownload Include="Microsoft.NETCore.App.Ref" Version="[10.0.0]" />
</ItemGroup>

• MSBuild properties
  • <AnnotatedReferenceAssemblyVersion>: Specifies the version of Microsoft.NETCore.App.Ref to obtain nullability information from. This is required if there are multiple PackageDownload versions of Microsoft.NETCore.App.Ref.
  • <GenerateNullableAttributes>: Set to True to include definitions of nullability attributes in the build; otherwise, False to exclude the definitions. The default value is True.
• MSBuild items
  • <UnannotatedReferenceAssembly>: Specifies reference assemblies to annotate. This is only required for assemblies that are not automatically annotated by this package.

• Binaries (NuGet)
• Release Notes
• License