Regressions on trunk at revision 255470 vs revision 255464

[H.J. Lu Intel64 Core i7]

New failures:

New passes:
FAIL: gcc.dg/builtin-stringop-chk-9.c  (test for warnings, line 125)
FAIL: gcc.dg/builtin-stringop-chk-9.c  (test for warnings, line 133)
FAIL: gcc.dg/builtin-stringop-chk-9.c  (test for warnings, line 141)
FAIL: gcc.dg/builtin-stringop-chk-9.c  (test for warnings, line 149)