[Bug target/77687] frame access after release without redzone on powerpc

["hainque at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77687

--- Comment #2 from Olivier Hainque <hainque at gcc dot gnu.org> ---
Thanks for stepping in Segher ! Much appreciated :-)

FWIW, I have just attached the bandaid patch we're currently
using on our gcc-6 based compilers. It's more brutal than the
original suggestion on the referenced thread, which seemed
fragile on a couple of accounts. This one is way simpler,
both conceptually and implementation-wise, intended to be
temporary until we devise a better resolution.

I had started on an alternate resolution you suggested. Just
didn't have the opportunity to get to finish it. I can post the
partial patches if you believe that could be useful.

But maybe we'll converge on something else entirely anyway.

Olivier