patch applied (ghc): GHC API: add checkAndLoadModule

[Simon Marlow]

Tue Nov  6 06:01:21 PST 2007  Simon Marlow <simonmar at microsoft.com>
  * GHC API: add checkAndLoadModule
  Does what the name suggests: it performs the function of both
  checkModule and load on that module, avoiding the need to process each
  module twice when checking a batch of modules.  This will make Haddock
  and ghctags much faster.
  
  Along with this is the beginnings of a refactoring of the HscMain
  interface.  HscMain now exports functions for separately running the
  parser, typechecher, and generating ModIface and ModDetails.
  Eventually the plan is to complete this interface and use it to
  replace the existing one.

    M ./compiler/deSugar/Desugar.lhs -36 +5
    M ./compiler/iface/MkIface.lhs -11 +101
    M ./compiler/main/GHC.hs -22 +67
    M ./compiler/main/HscMain.lhs -89 +94
    M ./compiler/main/HscTypes.lhs -2 +5
    M ./compiler/main/TidyPgm.lhs -9 +29
    M ./compiler/typecheck/TcRnDriver.lhs -2 +2