[Bug target/68163] GCC on power8 does not issue the stxsspx instruction on power8

[meissner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68163

--- Comment #1 from Michael Meissner <meissner at gcc dot gnu.org> ---
Created attachment 40691
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=40691&action=edit
Proposed patch to fix the problem.

I believe this patch fixes the problem.

Note, I am going on vacation, and won't return until the end of February, so I
won't be submitting the patch until I get back (unless somebody else wants to
verify that it works and submits it).