Pervasives: define [min_int] and [max_int] without assuming that integers are either 31 or 63 bits.
    
    (Patch by Jérôme Vouillon)
    
    Js_of_ocaml has 32 bit integers. Currently, it patches the bytecode,
    just to get the correct values for [min_int] and [max_int]. It would be
    simpler if this was not necessary.
    
    git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14477 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02