second part of Benoît Vaugon's format+gadts patch
    
    To finish the bootstrap cycle, run:
    
      make library-cross
      make promote
      make partialclean
      make core
    
      make library-cross
      make promote-cross
      make partialclean
      make ocamlc ocamllex ocamltools
    
      make library-cross
      make promote
      make partialclean
      make core
      make compare
    
    git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14810 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02