Regressions on trunk at revision 172805 vs revision 172765

[H.J. Lu ia32 Core 2/i7]

New failures:

New passes:
FAIL: gcc.dg/guality/vla-1.c  -O2 -flto  line 17 sizeof (a) == 6
FAIL: gfortran.dg/module_write_1.f90  -O  (internal compiler error)
FAIL: gfortran.dg/module_write_1.f90  -O  (test for excess errors)