Regressions on trunk at revision 171519 vs revision 171456

[H.J. Lu ia32]

New failures:
FAIL: boehm-gc.c/thread_leak_test.c -O2 (test for excess errors)
FAIL: gcc.dg/vect/pr38529.c (internal compiler error)
FAIL: gcc.dg/vect/pr38529.c (test for excess errors)
FAIL: gcc.dg/vect/pr38529.c scan-tree-dump-times vect "OUTER LOOP VECTORIZED" 1

New passes:
FAIL: gcc.dg/guality/sra-1.c  -O2 -flto  line 43 a.j == 14