Regressions on trunk at revision 178596 vs revision 178586

[Kirill Yukhin [ia32 Core i7 AVX]]

New failures:
FAIL: gcc.dg/vect/no-vfa-vect-37.c scan-tree-dump-times vect "can't determine dependence" 2
FAIL: gcc.dg/vect/no-vfa-vect-79.c scan-tree-dump-times vect "can't determine dependence" 1
FAIL: gcc.dg/vect/vect-outer-2b.c -flto scan-tree-dump-times vect "strided access in outer loop" 1
FAIL: gcc.dg/vect/vect-outer-2b.c scan-tree-dump-times vect "strided access in outer loop" 1

New passes:
FAIL: gcc.dg/vect/no-vfa-vect-37.c scan-tree-dump-times vect "can't determine dependence between" 2
FAIL: gcc.dg/vect/no-vfa-vect-79.c scan-tree-dump-times vect "can't determine dependence between" 1
FAIL: gcc.dg/vect/vect-outer-2b.c -flto scan-tree-dump-times vect "strided access in outer loop." 1
FAIL: gcc.dg/vect/vect-outer-2b.c scan-tree-dump-times vect "strided access in outer loop." 1