Regressions on trunk at revision 206191 vs revision 206178

[H.J. Lu ia32 Core i7]

New failures:

New passes:
FAIL: 17_intro/headers/c++200x/stdc++.cc (test for excess errors)
FAIL: 17_intro/headers/c++200x/stdc++_multiple_inclusion.cc (test for excess errors)
FAIL: gcc.dg/vect/costmodel/i386/costmodel-fast-math-vect-pr29925.c scan-tree-dump-times vect "vectorized 1 loops" 1
FAIL: gcc.dg/vect/costmodel/i386/costmodel-vect-31.c scan-tree-dump-times vect "vectorization not profitable" 1
FAIL: gcc.dg/vect/costmodel/i386/costmodel-vect-31.c scan-tree-dump-times vect "vectorized 3 loops" 1
FAIL: gcc.target/i386/avx2-cvt-2.c scan-tree-dump-times vect "note: vectorized 1 loops in function" 6
FAIL: gcc.target/i386/avx-cvt-2.c scan-tree-dump-times vect "note: vectorized 1 loops in function" 6
FAIL: gcc.target/i386/avx-cvt-3.c scan-tree-dump-times vect "note: vectorized 1 loops in function" 6
FAIL: gcc.target/i386/pr46295.c scan-assembler-times avx_vzeroupper 1
FAIL: gcc.target/i386/sse2-cvt-2.c scan-tree-dump-times vect "note: vectorized 1 loops in function" 6