Regressions on trunk at revision 246835 vs revision 246826

[Intel Automatic Testing System [ia32 Core AVX2]]

New failures:

New passes:
FAIL: g++.dg/pr80374.C  -std=c++11 (test for excess errors)
FAIL: g++.dg/pr80374.C  -std=c++14 (test for excess errors)
FAIL: g++.dg/pr80374.C  -std=c++98 (test for excess errors)