Engine: F*: impl missing bounds on trait generic types

[W95Psp]

The following Rust snippet:

trait TraitA {}
trait TraitB<T: TraitA> {}

impl TraitA for () {}
impl TraitB<()> for () {}

Open this code snippet in the playground

Extracts to the following F*:

class t_TraitA (v_Self: Type0) = {
  __marker_trait_t_TraitA:Prims.unit
}

[@@ FStar.Tactics.Typeclasses.tcinstance]
let impl_TraitA_for_tuple_: t_TraitA
Prims.unit = { __marker_trait = () }

class t_TraitB
  (v_Self: Type0) (v_T: Type0)
  = {
  [@@@ FStar.Tactics.Typeclasses.no_method]_super_9060164045790606315:t_TraitA
  v_T
}

[@@ FStar.Tactics.Typeclasses.tcinstance]
let impl_1: t_TraitB Prims.unit Prims.unit =
  { __marker_trait = () }

impl_1 lacks a super field.