Restore RNG states for composable reentrant activation checkpointing (#91265)
This allows ops like randperm to behave the same during re-computation.
Differential Revision: [D42196758](https://our.internmc.facebook.com/intern/diff/D42196758/)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/91265
Approved by: https://github.com/awgu
