One more change to sim/common/cgen.sh

[Ben Elliston]

Just one. :-)

I'd like to add another action to cgen.sh -- to generate the semantics files
for a simulator.  Since you have a choice between functions and a switch (or
both), it will be necessary to specify at *least* one of these via the
$extrafiles variable.

I have also considered the possibility of extending the "decode" action to
do this.  Thoughts?

Ben