patch applied (ghc): Teach :print to follow references (STRefs and IORefs)

[Pepe Iborra]

Tue Dec  4 02:55:11 PST 2007  Pepe Iborra <mnislaih at gmail.com>
  * Teach :print to follow references (STRefs and IORefs)
  
  Prelude Data.IORef> :p l
  l = (_t4::Maybe Integer) : (_t5::[Maybe Integer])
  Prelude Data.IORef> p <- newIORef l
  Prelude Data.IORef> :p p
  p = GHC.IOBase.IORef (GHC.STRef.STRef {((_t6::Maybe Integer) :
                                          (_t7::[Maybe Integer]))})
  Prelude Data.IORef> :sp p
  p = GHC.IOBase.IORef (GHC.STRef.STRef {(_ : _)})
  
  
  I used braces to denote the contents of a reference.
  Perhaps there is a more appropriate notation?

    M ./compiler/ghci/Debugger.hs -1 +5
    M ./compiler/ghci/RtClosureInspect.hs -25 +55