Support AbstractFloat(::StaticBool)

[oschulz]

I ran into

julia> log(static(true))
ERROR: MethodError: no method matching AbstractFloat(::True)

Since Base supports AbstractFloat(::Bool) I think it would make sense to support AbstractFloat(::StaticBool) as well.

[Tokazama]

Sounds good to me

[oschulz]

Same for Float64(::True) and so on.