Regressions on trunk at revision 170192 vs revision 170178

[H.J. Lu Intel64-profiled]

New failures:

New passes:
FAIL: gcc.dg/guality/vla-2.c  -O1  line 25 sizeof (a) == 6 * sizeof (int)
FAIL: gcc.dg/guality/vla-2.c  -O3 -fomit-frame-pointer  line 25 sizeof (a) == 6 * sizeof (int)
FAIL: gcc.dg/guality/vla-2.c  -O3 -g  line 25 sizeof (a) == 6 * sizeof (int)
FAIL: gcc.dg/guality/vla-2.c  -Os  line 25 sizeof (a) == 6 * sizeof (int)