Regressions on trunk at revision 172788 vs revision 172780

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

New failures:
FAIL: gcc.dg/guality/vla-1.c  -O2 -flto  line 17 sizeof (a) == 6

New passes:
FAIL: gcc.dg/binop-xor1.c scan-tree-dump-times optimized "^" 1
FAIL: gcc.dg/binop-xor2.c scan-tree-dump-times optimized "^" 1
FAIL: gcc.dg/binop-xor3.c scan-tree-dump-times optimized "^" 1
FAIL: gcc.dg/binop-xor4.c scan-tree-dump-times optimized "^" 1
FAIL: gcc.dg/binop-xor5.c scan-tree-dump-times optimized "^" 1
FAIL: gfortran.dg/module_write_1.f90  -O  (internal compiler error)
FAIL: gfortran.dg/module_write_1.f90  -O  (test for excess errors)