[NO-REVIEW] Use Zstandard for compressing singlefile assemblies

[rzikm]

This is an experiment that replaces DEFLATE with Zstandard in single-file published applications for compression of bundled managed assemblies.

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[rzikm]

@VSadov, @vitek-karas, @janvorli do you know what would be the easiest way to test/benchmark this kind of change?

[am11]

@VSadov, @vitek-karas, @janvorli do you know what would be the easiest way to test/benchmark this kind of change?

./build.sh clr+libs+packs -c Release, extract artifacts/packages/Shipping/xxx/dotnet-runtime-xxx.tar.gz into ./.dotnet2 and copy sdk dir ./.dotnet/sdk to ./dotnet2/sdk, adjust the versioned folder to match the shared framework (either change sfx version to match sdk or the other way around; I don't remember exactly), then cd .. && runtime/.dotnet2/dotnet new console -n helloworld && cd helloworld && ../runtime/.dotnet2/dotnet publish -p:PublishSingleFile=true -o dist && dist/helloworld. If you see Hello World!, you pass! :)

[jkotas]

dotnet new console

For benchmarking, you may want to pick an app with more managed code, like self-contained ASP.NET webapi. We want to measure the binary and startup time (just make the app exit immediately and then you can just measure the time the process took to run).