[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, 1 insertions, 1 deletions

diff --git a/plugins/micromega/certificate.ml b/plugins/micromega/certificate.ml
index 2e32b00c25..24039c93c6 100644
--- a/plugins/micromega/certificate.ml
+++ b/plugins/micromega/certificate.ml
@@ -93,7 +93,7 @@ let dev_form n_spec  p =
 
 let rec fixpoint f x =
   let y' = f x in
-  if Pervasives.(=) y' x then y'
+  if (=) y' x then y'
   else fixpoint f y'
 
 let  rec_simpl_cone n_spec e =