All installed Haskell prgms have an inplace and an installed version
- GHC installs a range of compiled Haskell programs in addition to the actual compiler. To ensure that they all run on the platform targeted by the build (which may have different libraries installed than the build host), we need to make sure that all compiled Haskell code going into an install is build with the stage 1 compiler, not the bootstrap compiler. Getting this right is especially important on the Mac to enable builds that work on Mac OS X versions that are older than the one performing the build. - For all installed utils implemented in Haskell (i.e., ghc-pkg, hasktags, hsc2hs, runghc, hpc, and pwd) we compile two versions, an inplace version and a version for installation. The former is build by the bootstrap compiler during the stage 1 build and the latter is build by the stage 1 compiler during the stage 2 build. - This is really very much as the setup for ghc itself, only that we don't use separate stage1/ and stage2/ build directories. Instead, we clean before each build. CAVEAT: This only works properly if invoked from the toplevel Makefile. - Instead of UseStage1=YES (as used by the previous binary-dist-specific recompilation), we now use the same $(stage) variables as used for the compiler proper - to increase uniformity and to avoid extra conditionals for the install target.