[11u]: Backport of RFR 8211122: Reduce the number of internal classes made accessible to jdk.unsupported (and JDK-8205537 and JDK-8211121)

[Langer, Christoph]

> I'm nervous. Although I expect this won't cause any JCK compatibility
> issues, it is a behavioural change. I wonder if we should consider
> referring this one to the CSR team.

+1

The original issues didn't have CSRs attached but it really feels CSRish. Let me know whether I shall create CSRs as you're still sorting out the process.

Cheers
Christoph