[econstr] Continue consolidation of EConstr API under `interp`.

This commit was motivated by true spurious conversions arising in my
`to_constr` debug branch.

The changes here need careful review as the tradeoffs are subtle and
still a lot of clean up remains to be done in `vernac/*`.

We have opted for penalize [minimally] the few users coming from true
`Constr`-land, but I am sure we can tweak code in a much better way.

In particular, it is not clear if internalization should take an
`evar_map` even in the cases where it is not triggered, see the
changes under `plugins` for a good example.

Also, the new return type of `Pretyping.understand` should undergo
careful review.

We don't touch `Impargs` as it is not clear how to proceed, however,
the current type of `compute_implicits_gen` looks very suspicious as
it is called often with free evars.

Some TODOs are:

- impargs was calling whd_all, the Econstr equivalent can be either
  + Reductionops.whd_all [which does refolding and no sharing]
  + Reductionops.clos_whd_flags with all as a flag.

1 files changed, 1 insertions, 1 deletions

diff --git a/proofs/proof.ml b/proofs/proof.ml
index 04e707cd6..f5ff35eeb 100644
--- a/proofs/proof.ml
+++ b/proofs/proof.ml
@@ -432,7 +432,7 @@ module V82 = struct
           CList.nth evl (n-1)
       in
       let env = Evd.evar_filtered_env evi in
-      let rawc = Constrintern.intern_constr env com in
+      let rawc = Constrintern.intern_constr env sigma com in
       let ltac_vars = Glob_ops.empty_lvar in
       let sigma = Evar_refiner.w_refine (evk, evi) (ltac_vars, rawc) sigma in
       Proofview.Unsafe.tclEVARS sigma