Feature request: Show size of future on hover

[jplatte]

It would be very useful if the "show type size on hover" functionality was available for anonymous futures, i.e. the types of async blocks and return types of async fns (when hovering the function name, I guess).

[HKalbasi]

For supporting this we need to desugar async blocks into generators, which is probably also useful for some other features as well (e.g. mir).