Regressions on trunk at revision 258702 vs revision 258673

[H.J. Lu]

New failures:
FAIL: gcc.dg/vect/costmodel/x86_64/costmodel-pr84986.c scan-tree-dump vect "vectorized 1 loops"

New passes:
FAIL: gcc.dg/lto/chkp-ctor-merge c_lto_chkp-ctor-merge_0.o-c_lto_chkp-ctor-merge_0.o link,  -O2 -flto -fcheck-pointer-bounds -mmpx -nodefaultlibs -lc  (internal compiler error)
FAIL: gcc.dg/lto/chkp-ctor-merge c_lto_chkp-ctor-merge_0.o-c_lto_chkp-ctor-merge_0.o link,  -O2 -flto -fcheck-pointer-bounds -mmpx -nodefaultlibs -lc  (internal compiler error)
FAIL: libgomp.graphite/force-parallel-4.c scan-tree-dump-times graphite "2 loops carried no dependency" 1
FAIL: libgomp.graphite/force-parallel-4.c scan-tree-dump-times graphite "2 loops carried no dependency" 1
FAIL: libgomp.graphite/force-parallel-4.c scan-tree-dump-times graphite "2 loops carried no dependency" 1