synchronize the external declaration of Pervasives.float_of_bits with that of Int64 (#897)
synchronize the external declaration of Pervasives.float_of_bits with that of Int64 (#897)

that way the float_of_bits calls in Pervasives can use the unboxed version
yunxing/ocaml,gerdstolpmann/ocaml,gerdstolpmann/ocaml,yunxing/ocaml,msprotz/ocaml,yunxing/ocaml,yunxing/ocaml,gerdstolpmann/ocaml,msprotz/ocaml,msprotz/ocaml,msprotz/ocaml,gerdstolpmann/ocaml,yunxing/ocaml,gerdstolpmann/ocaml,msprotz/ocaml