Log Message:
Update ghc to 6.8.3.  Thanks to Donn Cave for bugfix patches.

Changes in 6.8.3:
* The arguments to ghc-pkg now understand lists and wildcards, and
  there is a new command ghc-pkg find-module.

* The filename completion in ghci is now more intelligent.

* We now look for GHCi config files in these locations:
    ./.ghci
    $HOME/.ghc/ghci.conf
    $HOME/.ghci

* You can now give multiple -e options to GHC.

* You can now use the -prof and -threaded flags together, although
  you cannot also use +RTS -N2.

* SCC names are no longer allowed to contain spaces, as some of the
  profiling tools break if they do.

* Various changes have been made to GHC's internals, so there are some
  differences in the API exposed by the ghc package. Most notably,
  checkAndLoadModule has now been implemented.