g
our own macros instead of using the predefined ones directly, we can
impose a bit more consistency, and somewhat isolate ourselves from
compiler differences.
<P>
It is relatively straightforward to add a new entry here.  But please try
to be consistent with the existing code.  In particular, 64-bit variants
of 32-bit architectures general are <I>not</i> treated as a new architecture.
Instead we explicitly test for 64-bit-ness in the few places in which it
matters.  (The notable exception here is <TT>I386<