Modify RuntimeEnvironment to use System.Runtime.InteropServices.RuntimeInformation

[pranavkm]

The code ported from Microsoft.Extensions.PlatformAbstractions contains a bunch of pinvokes for APIs that are available via the RuntimeInformation package. However the package has issues in RC2 where it does not bring in runtime binaries in desktop applications. This is fixed in RTM (https://github.com/dotnet/corefx/issues/7863).

[TheRealPiotrP]

I looked at the dependencies of Microsoft.Extensions.PlatformAbstractions. It does not have any dependencies back into CLI, so as long as the package references shipping CoreFx packages I don't have concern about the cycle for RC2.

[TheRealPiotrP]

since the PR is out, let's leave this in :)

[TheRealPiotrP]

Per conversation with @pranavkm this is tracking remaining work for RTM which will enable using RuntimeInformation in desktop projects. This is dependent on dotnet/corefx#7863 and so will be fixed in RTM once that is fixed.

[pranavkm]

I was looking at this again and there's a bunch of APIs in RuntimeInformation that we require (Unix distro name, OsVersion) that are internal to corefx. I'll file a work item to see if they are willing to make these APIs usable to us.

[pranavkm]

Here's the CoreFx work item: https://github.com/dotnet/corefx/issues/9011.

[TheRealPiotrP]

The CoreFx issue is still open, so moving this out of RTM.

[livarcocc]

We don't ship this out of the CLI anymore.