Moving the argument of CProdN/CLambdaN from binder_expr to local_binder_expr.

The motivations are:

- To reflect the concrete syntax more closely.
- To factorize the different places where "contexts" are internalized:
  before this patch, there is a different treatment of `Definition f
  '(x,y) := x+y` and `Definition f := fun '(x,y) => x+y`, and a hack
  to interpret `Definition f `pat := c : t`. With the patch, the fix
  to avoid seeing a variable named `pat` works for both `fun 'x =>
  ...` and `Definition f 'x := ...`.

The drawbacks are:

- Counterpart to reflecting the concrete syntax more closerly, there
  are more redundancies in the syntax. For instance, the case `CLetIn
  (na,b,t,c)` can appears also in the form `CProdN (CLocalDef
  (na,b,t)::rest,d)` and `CLambdaN (CLocalDef (na,b,t)::rest,d)`.
- Changes in the API, hence adaptation of plugins referring to `constr_expr` needed.

1 files changed, 1 insertions, 1 deletions

diff --git a/test-suite/output/PatternsInBinders.out b/test-suite/output/PatternsInBinders.out
index 95be04c32..6b09c3308 100644
--- a/test-suite/output/PatternsInBinders.out
+++ b/test-suite/output/PatternsInBinders.out
@@ -31,7 +31,7 @@ exists '(x, y) '(z, w), swap (x, y) = (z, w)
      : Prop
 both_z = 
 fun pat : nat * nat =>
-let '(n, p) as pat0 := pat return (F pat0) in (Z n, Z p) : F (n, p)
+let '(n, p) as x := pat return (F x) in (Z n, Z p) : F (n, p)
      : forall pat : nat * nat, F pat
 fun '(x, y) '(z, t) => swap (x, y) = (z, t)
      : A * B -> B * A -> Prop