[Bug testsuite/89834] New test case gcc.dg/vect/pr81740-2.c introduced in r269938 fails on power 7

[wschmidt at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89834

--- Comment #4 from Bill Schmidt <wschmidt at gcc dot gnu.org> ---
Thanks, I verified that the vectorization depends on vectorizing an unaligned
access, so I believe this is the correct fix.