closures

[BCS]

Reply to Jarrett,

> I think what's going on here is that the compiler will *only* allocate
> closures for nested functions. However allocating a closure for a
> delegate of a value object would be a nice addition.
> 

This will quickly devolve into the general escape analysts problem and here 
there be dragons. I think the correct solution is to say it's unsupported 
by calling this an escaping reference bug in the user code.