[Python-3000] Free list for small longs

["Martin v. Löwis"]

> My new
> sys._compact_freelists() deallocates the float and int blocks which do
> not contain a referenced object.

I wonder whether such a thing should run as a side effect of a full 
garbage collection, also. GC has a chance to free up arenas for good,
and allocated-but-unused blocks on arenas prevent Python from returning
them to the OS.

Regards,
Martin