patch applied (ghc): Do aggressive register coalescing

[Ben Lippmeier]

Mon Sep  3 04:51:49 PDT 2007  Ben.Lippmeier at anu.edu.au
  * Do aggressive register coalescing
  Conservative and iterative coalescing come next.

    M ./compiler/nativeGen/GraphColor.hs -11 +23
    M ./compiler/nativeGen/GraphOps.hs -16 +142
    M ./compiler/nativeGen/RegAllocColor.hs -3 +13
    M ./compiler/nativeGen/RegAllocStats.hs +23