Regressions on master at commit r12-5830 vs commit r12-5826 on Linux/x86_64

[H.J. Lu]

New failures:

New passes:
FAIL: g++.dg/cpp0x/decltype-bitfield1.C  -std=c++14 (test for excess errors)
FAIL: g++.dg/cpp0x/decltype-bitfield1.C  -std=c++14 (test for excess errors)
FAIL: g++.dg/cpp0x/decltype-bitfield1.C  -std=c++17 (test for excess errors)
FAIL: g++.dg/cpp0x/decltype-bitfield1.C  -std=c++17 (test for excess errors)
FAIL: g++.dg/cpp0x/decltype-bitfield1.C  -std=c++2a (test for excess errors)
FAIL: g++.dg/cpp0x/decltype-bitfield1.C  -std=c++2a (test for excess errors)