This change brings in a new approach to managing address space.
It wraps the Pal with a power of two reservation system, that
guarantees all returned blocks are naturally aligned to their size. It
either lets the Pal perform aligned requests, or over allocates and
splits into power of two blocks.
The PAL API previously allowed for returning more memory than asked for.
This was when the PAL performed the alignment work, now this is done in
large alloc, so removing from the PAL.
