Regressions on trunk at revision 249495 vs revision 249449

[H.J. Lu]

New failures:
FAIL: gcc.dg/tree-ssa/ipa-split-5.c scan-tree-dump optimized "part"
FAIL: gcc.dg/tree-ssa/ipa-split-5.c scan-tree-dump optimized "part"

New passes:
FAIL: g++.dg/cpp0x/constexpr-cast.C  -std=c++11  (test for errors, line 10)
FAIL: g++.dg/cpp0x/constexpr-cast.C  -std=c++11 (test for excess errors)
FAIL: g++.dg/cpp0x/constexpr-cast.C  -std=c++14  (test for errors, line 10)
FAIL: g++.dg/cpp0x/constexpr-cast.C  -std=c++14 (test for excess errors)