anchor.diff:                  let typ, meth = getTypeAndMethod m
                   NewDelegate(Some This, typ, meth)
               else failwithf "TransformIdentifierName: unhandled IMethodSymbol conversion: %A" conv 
  +        | :? IDiscardSymbol ->
  +            Undefined
           | null -> 
               err x.Node "TransformIdentifierName: Symbol is null. This is possibly a Roslyn bug, putting it in parentheses can help."
           | _ -> 
  
positive.code:         | :? IPropertySymbol as leftSymbol ->
              let typ, setter = getTypeAndMethod leftSymbol.SetMethod
              //if leftSymbol.IsIndexer // TODO property indexers
              
              match x.Kind with
              | AssignmentExpressionKind.SimpleAssignmentExpression ->
                  let right = x.Right |> trR.TransformExpression
  
negative.code:         let v = Id.New ("$m", mut = false)
          let rec trDesignation v e =
              match IgnoreExprSourcePos e with
              | Var x ->
                  VarSet(x, v) 
              | NewVar(nv, _) ->
                  NewVar(nv, v) 
              | NewArray ds ->
  