patch applied (ghc): Fixed a bug in the datacon names extension in the dynamic linker

[Pepe Iborra]

Thu Feb 15 10:19:34 PST 2007  Pepe Iborra <mnislaih at gmail.com>
  * Fixed a bug in the datacon names extension in the dynamic linker
  
  My code was doing unnecessary work when trying to get hold of all the BCOs in order to sniff the datacon names.
  This involved calculating the transitive closure of a relation and was causing a huge performance slowdown in GHCi, as benchmarks uncovered. It turns out that this calculation was unnecessary.
  

    M ./compiler/ghci/Linker.lhs -10 +2