Regressions on trunk at revision 254507 vs revision 254501

[H.J. Lu ia32 Core i7]

New failures:

New passes:
FAIL: g++.dg/pr50763-3.C  -std=gnu++11 (test for excess errors)
FAIL: g++.dg/pr50763-3.C  -std=gnu++14 (test for excess errors)
FAIL: g++.dg/pr50763-3.C  -std=gnu++98 (test for excess errors)