Switch to using System.Runtime.InteropServices.RuntimeInformation where appropriate

[analogrelay]

(this can be done in RTM)

/cc @muratg

[Eilon]

@BrennanConroy can you figure out what we need to do here?

[davidfowl]

We can't do anything until we get new BCL packages.

[Eilon]

Ok, hopefully today.

[muratg]

This should be doable now.

[muratg]

@BrennanConroy unblocked?

[BrennanConroy]

Nope, we need to get the RC3 System.* packages

[natemcmaster]

This is the cause of dotnet/efcore#5483

[BrennanConroy]

OSVersion isn't supported yet https://github.com/dotnet/corefx/issues/4741
RuntimeType does not exist in RuntimeInformation, we use if to test for CLR, CoreCLR, or Mono
https://github.com/dotnet/corefx/issues/8920

[pranavkm]

@BrennanConroy where do we use those two properties?

[BrennanConroy]

Testing, EntityFramework, MusicStore, Performance, Hosting

[BrennanConroy]

Should I leave the spots that use OsVersion and RuntimeType and remove the references to the other types on the RuntimeEnvironment type?

[BrennanConroy]

Done, will make an issue in Common for removing the RuntimeEnvironment.Sources package once RuntimeInformation has more features.