Regressions on trunk at revision 175589 vs revision 175287

[Kirill Yukhin [ia32 Core i7 AVX]]

New failures:
FAIL: g++.dg/cpp0x/constexpr-ptrmem.C (test for excess errors)
FAIL: g++.dg/tree-ssa/fwprop-align.C scan-tree-dump-times forwprop2 "& 1" 0

New passes:
FAIL: g++.dg/torture/pr43879-1_1.C  -O1  execution test
FAIL: g++.dg/torture/pr43879-1_1.C  -O2  execution test
FAIL: g++.dg/torture/pr43879-1_1.C  -O3 -fomit-frame-pointer  execution test
FAIL: g++.dg/torture/pr43879-1_1.C  -O3 -g  execution test
FAIL: g++.dg/torture/pr43879-1_1.C  -Os  execution test