patch applied (ghc): Add -ddump-mod-cycles to -M behaviour

[Simon Peyton Jones]

Thu Mar 22 05:28:59 PDT 2007  simonpj at microsoft.com
  * Add -ddump-mod-cycles to -M behaviour
  
  This patch adds a flag -ddump-mod-cycles to the "ghc -M" dependency analyser.
  
  The effect of
  	ghc -M -ddump-mod-cycles
  is to dump a list of cycles foud in the module graph.  The display is
  trimmed so that only dependencies within the cycle are shown; and the
  list of modules in a cycle is itself sorted into dependency order, so that
  it is easy to track the chain of dependencies.
  
  Open question: should the flag be "-ddump-mod-cycles" or "-optdep-dump-mod-cycles"?  For this reason I have not yet added to the documentation.
  

    M ./compiler/main/DriverMkDepend.hs -5 +69
    M ./compiler/main/DynFlags.hs +2