Support save/restore of context on list run/finish.
Don't allow save/restore ctx while list running.
Restore context even without an interrupt.
Use a saved ctx not break/continue in PPGe.
Save the base address in signal calls.

It's not saved in regular calls but it is in signal ones.
Merge pull request #3856 from unknownbrackets/ge-minor

Save/restore GE ctx when lists request it, use in PPGe, and minor signal call fix