Flagging Socket.Connect as not support on Linux and macOS

[paul-777]

I don't understand why it flags elements from the .NetCore main implementation as "isn't supported on Linux and macOS" in this case the Socket.Connect method. Surely the point is that the main .Net Core api is supported on all platforms and that platform specific functionality went elsewhere. Looking at the .Net Core source the method doesn't throw a PlatformNotSupportedException?

Additionally there are other cases like use of PerformanceCounters from the compatibility pack which it doesn't detect as problems.