Regressions on trunk at revision 255495 vs revision 255461

[H.J. Lu Intel64]

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)