Simplify the build system, and remove 2 phases

Simplify the build system, and remove 2 phases
From
    http://hackage.haskell.org/trac/ghc/wiki/Building/Architecture/Idiom/PhaseOrdering

Phase 0:
    Includes: package-data.mk files for things built by the
              bootstrapping compiler.
    Builds:   the dependency files for hsc2hs and genprimopcode. We need
              to do this now, as hsc2hs needs to be buildable in phase 1's
              includes (so that we can make the hpc library's .hs source
              files, which in turn is necessary for making its dependency
              files), and genprimopcode needs to be buildable in phase 1's
              includes (so that we can make the primop-*.hs-incl files,
              which are sources for the stage1 compiler library, and thus
              necessary for making its dependency files).
Phase 1:
    Includes: dependency files for things built by the bootstrapping
              compiler.
    Builds:   package-data.mk files for everything else. Note that this
              requires configuring the packages, which means telling cabal
              which ghc to use, and thus the stage1 compiler gets built
              during this phase.
Phase "":
    Includes: dependency files for everything else.
    Builds:   Everything else.