Unreviewed patch for df.c/flow.c

[Daniel Berlin]

http://gcc.gnu.org/ml/gcc-patches/2001-08/msg01144.html

This should be pretty non-controversial, and shouldn't take very long
for someone to review.
I only care that it hasn't been reviewed because i've redone df.c to
use the iterative dataflow functions i submitted (IE using the fibheap
for the queues, etc), so i have to keep this patched version around
specifically to commit, which is a pain in the ass.
--Dan

-- 
"After they make styrofoam, what do they ship it in?
"-Steven Wright