[v3] -Weffc++ fixups

[Paolo Carlini]

Dhruv Matani wrote:

>4. bitmap_allocator is giving problems with linking when boostrapped as
>the default. Paolo is looking into it, but after seeing your patches, I
>have a feeling that it's happening because the explicit instantiations
>for the static is not there. Is my hunch valid?
>  
>
No, the problem is with the explicit *inizialization* of the static data 
members,
which must be unique and typically belongs to a *different* file.

Paolo.