patch applied (ghc): tightened some dataflow code as part of preparing a talk

[nr at eecs.harvard.edu]

Mon Sep 17 09:17:15 PDT 2007  Norman Ramsey <nr at eecs.harvard.edu>
  * tightened some dataflow code as part of preparing a talk

    M ./compiler/cmm/CmmSpillReload.hs -17 +28
    M ./compiler/cmm/ZipDataflow.hs -2 +1