Regressions on trunk at revision 234575 vs revision 234546

[H.J. Lu ia32 -fpic]

New failures:
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

New passes: