Regressions on trunk at revision 172894 vs revision 172891

[H.J. Lu Intel64 Core 2/i7]

New failures:
FAIL: gcc.dg/guality/vla-1.c  -O2 -flto  line 17 sizeof (a) == 6
FAIL: gcc.dg/guality/vla-1.c  -O2 -flto -flto-partition=none  line 17 sizeof (a) == 6
FAIL: gcc.target/i386/pr48723.c (internal compiler error)
FAIL: gcc.target/i386/pr48723.c (test for excess errors)

New passes:
FAIL: g++.dg/other/i386-9.C (internal compiler error)
FAIL: g++.dg/other/i386-9.C (internal compiler error)
FAIL: g++.dg/other/i386-9.C (test for excess errors)
FAIL: g++.dg/other/i386-9.C (test for excess errors)