[Bug tree-optimization/63467] should have asm statement that does not prevent vectorization

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63467

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Try asm volatile ("":::); instead.  Asms without any ::: are considered
clobbering memory.