Should we add new CSharpVersion7 option in [Language](https://github.com/PowerShell/PowerShell/blob/master/src/Microsoft.PowerShell.Commands.Utility/commands/utility/AddType.cs#L43) enum in Add-Type cmdlet? And why we use "#if CORECLR" in the enum?
Should we add new CSharpVersion7 option in Language enum in Add-Type cmdlet?
And why we use "#if CORECLR" in the enum?