Some regressions from the dataflow merge

[Richard Guenther]

On ia64 SPEC2000 I see fma3d and applu now miscompare, and we have
on x86_64 some performance regressions with Botan (a collection of
cryptographic algorithms (see 
http://www.suse.de/~gcctest/c++bench/botan/)) - those are reasonably
small enough to investigate, but wait another day in case its just noise.

Otherwise things look smooth as expected.

Richard.