Regressions on trunk at revision 229792 vs revision 229790

[Bill Schmidt]

New failures:
FAIL: boehm-gc.c/gctest.c -O2 execution test
FAIL: runtime

New passes:
FAIL: gfortran.dg/null_1.f90   -O   (test for errors, line 12)
FAIL: gfortran.dg/null_1.f90   -O  (test for excess errors)