Performance improvement after symbol table changes

[Rik]

jwe,

This isn't a real benchmark, but I have been using it periodically back to
version 3.2.

a = 1; b = 1; tic; for i=1:1000; for j=1:1000; a = a + b + 1.0; end; end; toc

On my machine, the RC1 candidate clocks in at 1.57 seconds.

The development branch clocks in at 1.2 seconds.

That is a 23.5% drop in run time.

Nice work,
Rik