Regressions on trunk at revision 234929 vs revision 234894

[H.J. Lu Intel64]

New failures:

New passes:
FAIL: gcc.dg/tree-ssa/prefetch-5.c scan-tree-dump-times aprefetch "Issued prefetch" 2
FAIL: gcc.dg/tree-ssa/prefetch-5.c scan-tree-dump-times aprefetch "Not prefetching" 1