Regressions on trunk at revision 239179 vs revision 239171

[H.J. Lu Intel64]

New failures:

New passes:
FAIL: g++.dg/cpp0x/constexpr-cast.C  -std=c++11  (test for errors, line 10)
FAIL: g++.dg/cpp0x/constexpr-cast.C  -std=c++11  (test for errors, line 11)
FAIL: g++.dg/cpp0x/constexpr-cast.C  -std=c++11 (test for excess errors)
FAIL: g++.dg/cpp0x/constexpr-cast.C  -std=c++14  (test for errors, line 10)
FAIL: g++.dg/cpp0x/constexpr-cast.C  -std=c++14  (test for errors, line 11)
FAIL: g++.dg/cpp0x/constexpr-cast.C  -std=c++14 (test for excess errors)