PROTOTYPE(DefaultInterfaceImplementation): commented out NoBuild property to work around a build error:
roslyn\.dotnet\sdk\3.0.100-preview4-010391\Sdks\Microsoft.NET.Sdk\targets\Microsoft.NET.Sdk.targets(112,5): error NETSDK1085: The 'NoBuild' property was set to true but the 'Build' target was invoked. [roslyn\src\Tools\ILAsm\IlAsmDeploy.csproj]