In order to build a self-contained .NET Core app (see here for more info), we need to ensure that a CoreClr package is brought in by the dependency graph. And we need to copy in a DotNetHost (dotnet.exe) to execute the app.

See https://github.com/dotnet/cli/blob/6b54ae0bcc5c63e7c989ac19d851f234f9172bea/src/Microsoft.DotNet.Compiler.Common/Executable.cs#L102-L107 for the previous CLI implementation.