Regressions on trunk at revision 201817 vs revision 201785

[Kirill Yukhin [Intel64 Core AVX-i]]

New failures:

New passes:
FAIL: g++.dg/ext/mv2.C -std=gnu++11 execution test
FAIL: g++.dg/ext/mv2.C -std=gnu++11 execution test
FAIL: g++.dg/ext/mv2.C -std=gnu++98 execution test
FAIL: g++.dg/ext/mv2.C -std=gnu++98 execution test