patch applied (ghc): make GHCi use base:Prelude, not just Prelude

[Simon Marlow]

Tue Mar 27 08:45:54 PDT 2007  Simon Marlow <simonmar at microsoft.com>
  * make GHCi use base:Prelude, not just Prelude
  The module that GHCi uses for its default scope should be exactly
  base:Prelude, not whatever Prelude is found on the search path.

    M ./compiler/ghci/InteractiveUI.hs -1 +1
    M ./compiler/main/GHC.hs -1 +1