proposal: reimplement Data.Graph.Inductive.Query.Dominators

[Bertram Felgenhauer]

Hi,

(this is Trac ticket #2227,
    http://hackage.haskell.org/trac/ghc/ticket/2227)

As pointed out at
    http://www.haskell.org/pipermail/haskell-cafe/2008-April/041739.html
ff., Data.Graph.Inductive.Query.Dominators.dom is buggy. Furthermore,
it's slow, so instead of submitting the quick fix from that thread,
I've rewritten the module from scratch using a more efficient algorithm.

The algorithm works by calculating the immediate dominators of the graph
nodes first, so the patch also adds a function that returns those. It
should be handy for flow graph analysis. 

Deadline for discussion ... is a week sufficient?
That would be April 28th.

regards,

Bertram