Mainline mt_allocator performance on sparc-sun-solaris2.8

[Benjamin Kosnik]

> - I noticed that the following lines in mt_allocator.h that I
>   expected to see in mt_allocator.cc instead.  Do I misunderstand
>   that this extension instantiates the entire template in the
>   translation unit (and thus that object file)?

These are forward declarations.

>  // Data describing the underlying memory pool, parameterized on
>  // threading support.
>  template<bool _Thread>
>    class __pool;
>
>  template<>
>    class __pool<true>;
>
>  template<>
>    class __pool<false>;

... explicit instantiations don't have "template<>"

best,
benjamin