[core] [api] Support OCaml 4.08

The changes are large due to `Pervasives` deprecation:

- the `Pervasives` module has been deprecated in favor of `Stdlib`, we
  have opted for introducing a few wrapping functions in `Util` and
  just unqualified the rest of occurrences. We avoid the shims as in
  the previous attempt.

- a bug regarding partial application have been fixed.

- some formatting functions have been deprecated, but previous
  versions don't include a replacement, thus the warning has been
  disabled.

We may want to clean up things a bit more, in particular
w.r.t. modules once we can move to OCaml 4.07 as the minimum required
version.

Note that there is a clash between 4.08.0 modules `Option` and `Int`
and Coq's ones. It is not clear if we should resolve that clash or
not, see PR #10469 for more discussion.

On the good side, OCaml 4.08.0 does provide a few interesting
functionalities, including nice new warnings useful for devs.

1 files changed, 2 insertions, 2 deletions

diff --git a/plugins/micromega/simplex.ml b/plugins/micromega/simplex.ml
index 15fb55c007..4c95e6da75 100644
--- a/plugins/micromega/simplex.ml
+++ b/plugins/micromega/simplex.ml
@@ -587,7 +587,7 @@ let cut env rmin sol vm (rst:Restricted.t)  tbl (x,v) =
              Printf.printf "This is a cutting plane for %a:" LinPoly.pp_var x;
              Printf.printf " %a\n"  WithProof.output (v,prf);
            end;
-         if Pervasives.(=) (snd v) Eq
+         if (=) (snd v) Eq
          then (* Unsat *) Some (x,(v,prf))
          else
            let vl = (Vect.dotproduct (fst v) (Vect.set 0 (Int 1) sol)) in
@@ -651,7 +651,7 @@ let integer_solver lp =
        match find_cut (!nb mod 2) env cr (*x*) sol vm rst tbl with
        | None -> None
        | Some(cr,((v,op),cut)) ->
-          if Pervasives.(=) op Eq
+          if (=) op Eq
           then (* This is a contradiction *)
             Some(Step(vr,CutPrf cut, Done))
           else