TempAlloc: Request for Review For Inclusion in core.memory

[dsimcha]

== Quote from Andrej Mitrovic (andrej.mitrovich at gmail.com)'s article
> Ok, perhaps you should put a note in the docs about falling back to
> the C heap. Or maybe that's just common sense for people in the
> know-how?

Right.  This is roughly equivalent to allocating a new segment.  I might put more
details into the docs about the heuristics used, but I'm not sure how much I
should document them.  They're somewhat complicated, may change, and are
implementation details.  On the other hand, the whole point of TempAlloc is a
performance optimization, and knowing such details is useful for predicting
performance.  On the third hand, it's open source.  If you really want to know
**exactly** how it works instead of just how to use it, you can always read the code.