[gclist] efficient allocation of blocks of different size

[Charles Fiterman]

> Hi wizards
> 
> What is the state of the art in efficient allocation and storage
> management for blocks of different size, especially special sizes,
> i.e. large numbers of a few sizes?

For small sizes our collector will create a 4K block full of a size
such as 12 bytes in responce to the first allocation. You can do
this kind of thing directly. We find it very efficient in both
speed and the reduction of fragmentation which amounts to space.

Generational collectors allocate by decrementing a pointer and
comparing it to a limit. This is even better.