Re: si:reorder-memory in Genera 7.2

[Mabry Tyson <TYSON@WARBUCKS.AI.SRI.COM>]

We should probably let the experts speak but my experience has been that
if you don't do a :OPTIMIZE WORLD before saving out a world (incremental
or complete) and you later build an incremental world based on that but
in which you do a :OPTIMIZE WORLD, the second world is much larger than
its minimal size.  I presume the reason is that it reorders everything
that hasn't been reordered already.  In particular, that presumably
reorders stuff that was in the first world but which hasn't otherwise
been changed.  Therefore those pages are now changed and so go into the
second incremental world, making it larger.

(Gee, wouldn't it be nice if :SAVE WORLD had options for doing the
:OPTIMIZE WORLD itself (and maybe SI:FULL-GC on complete saves).