Provide internal attributes to WPF temporary assembly

Author: jnm2

TunnelVisionLabs.ReferenceAssemblyAnnotator/TunnelVisionLabs.ReferenceAssemblyAnnotator.targets

@@ -16,6 +16,9 @@
   <ItemGroup Condition="'$(GenerateNullableAttributes)' == 'true' AND Exists($(NullableAttributesPath))">
     <Compile Include="$(NullableAttributesPath)" Visible="false" />
 
+    <!-- Workaround for https://github.com/dotnet/wpf/issues/810 -->
+    <_GeneratedCodeFiles Include="$(NullableAttributesPath)" Visible="false" Condition="'$(UseWPF)' == 'true'" />
+
     <!-- Make sure the source file is embedded in PDB to support Source Link -->
     <EmbeddedFiles Condition="'$(DebugType)' != 'none'" Include="$(NullableAttributesPath)" />
   </ItemGroup>