[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/vect.ml b/plugins/micromega/vect.ml
index 4b2bc66eb7..a5f3b83c48 100644
--- a/plugins/micromega/vect.ml
+++ b/plugins/micromega/vect.ml
@@ -148,7 +148,7 @@ let rec add (ve1:t) (ve2:t)  =
   match ve1 , ve2 with
   | [] , v | v , [] -> v
   | (v1,c1)::l1 , (v2,c2)::l2 ->
-     let cmp = Pervasives.compare v1 v2 in
+     let cmp = Util.pervasives_compare v1 v2 in
      if cmp == 0 then
        let s = add_num c1 c2 in
        if eq_num (Int 0) s
@@ -163,7 +163,7 @@ let rec xmul_add (n1:num) (ve1:t) (n2:num) (ve2:t) =
   | [] , _ -> mul n2 ve2
   | _ , [] -> mul n1 ve1
   | (v1,c1)::l1 , (v2,c2)::l2 ->
-     let cmp = Pervasives.compare v1 v2 in
+     let cmp = Util.pervasives_compare v1 v2 in
      if cmp == 0 then
        let s = ( n1 */ c1) +/ (n2 */ c2) in
        if eq_num (Int 0) s