Regressions on trunk at revision 266418 vs revision 266409

[H.J. Lu (ia32 Core i7)]

New failures:

New passes:
FAIL: gcc.dg/Wbuiltin-declaration-mismatch-4.c (test for excess errors)
FAIL: gcc.dg/Wbuiltin-declaration-mismatch-4.c  (test for warnings, line 80)
FAIL: gcc.dg/Wbuiltin-declaration-mismatch-4.c  (test for warnings, line 82)