[PATCH v3 18/18] powerpc/64s: Clear gprs on interrupt routine entry

[Rohan McLure]

> What about arch/powerpc/kernel/exceptions-64e.S, no change required 
> inside it ? As interru_64.S applies to both 64s and 64e, I would have 
> expected changes in exceptions_64e too.

As it stands the changes in interrupt_64.S cause non-volatiles to be
unconditionally restored. This may lead to a performance regression on
Book3E, as previously interrupt_return_srr would restore non-volatiles
only after handling a signal, otherwise assuming nvgprs to be intact.

As some Book3E systems do feature speculation, it makes sense to perform
the same mitigation on these systems as performed on Book3S systems.