return when desugaring to closures

[David Herman]

> Does the |var| within the lambda define a var in the function body,
> and does that var declaration hoist to the top of the function body?

Good catch, thank you. Since `lambda' is designed to have no implicit semantics, it can't introduce a new `var' frame. IOW, the `var' would still be hoisted to the nearest enclosing `function', not `lambda'. I'll add this to the wiki page.

Thanks,
Dave