Description
A fairly common request is for the editor to give IntelliSense for a particular version of PowerShell. For instance, a user on a Windows 10 machine with PowerShell 5.1 might want to emulate IntelliSense for a Windows 7 machine running PowerShell 2.0. It'd be nice if we could switch to a compatibility mode which provides cmdlet and .NET IntelliSense based on what's available on the target platform. This would also be helpful for those writing scripts using PSES on Linux and macOS since PowerShell v6 has a different cmdlet/featureset than any of the Windows PowerShell versions.
One other benefit of this feature is that it could allow us to do IntelliSense without an active runspace. This would be helpful in cloud based-editing scenarios because a hosted PSES service could give IntelliSense without the need for a running PowerShell session.
We should figure out how to integrate this into PSES before 1.0 just in case it requires any design changes. If we can implement this without changing any APIs then we could potentially push the implementation past 1.0.
/cc @kapilmb