[Bug target/95704] PPC: int128 shifts should be implemented branchless

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95704

--- Comment #4 from Segher Boessenkool <segher at gcc dot gnu.org> ---
It no longer generates that rldicl in GCC 9 (or GCC 10).

You do get straight-line code already if you use -mcpu=power9, btw
(isel; and not totally awful code, but it isn't super of course).