Regressions on 4.5 at revision 161128 vs revision 160958

[H.J. Lu ia64]

New failures:
FAIL: gcc.c-torture/execute/builtins/snprintf-chk.c compilation,  -O2 -flto 
FAIL: gfortran.dg/unpack_bounds_2.f90  -O3 -fomit-frame-pointer -funroll-all-loops -finline-functions  (test for excess errors)

New passes:
FAIL: gcc.c-torture/compile/limits-fndefn.c  -O3 -g  (test for excess errors)
FAIL: gfortran.dg/char_result_13.f90  -O1  (test for excess errors)
FAIL: tr1/6_containers/unordered_set/swap/2.cc (test for excess errors)
WARNING: program timed out.