Fix #8119: anomalies in vm_compute with let and evars.

There were actually two broken things with VM + evars, the fixes are:
- Do not pass let-bound arguments to evars.
- Use the right order for evar arguments.

Native compilation seems to be suffering from the same shortcomings, I will
open a separate bug and adapt the PR.

1 files changed, 3 insertions, 0 deletions

diff --git a/kernel/cbytegen.ml b/kernel/cbytegen.ml
index 6677db2fd9..981444ac5e 100644
--- a/kernel/cbytegen.ml
+++ b/kernel/cbytegen.ml
@@ -501,6 +501,9 @@ let rec compile_lam env cenv lam sz cont =
       if Array.is_empty args then
         compile_fv_elem cenv (FVevar evk) sz cont
       else
+        (** Arguments are reversed in evar instances *)
+        let args = Array.copy args in
+        let () = Array.rev args in
         comp_app compile_fv_elem (compile_lam env) cenv (FVevar evk) args sz cont
 
   | Lconst (kn,u) -> compile_constant env cenv kn u [||] sz cont