patch for include/opcode/cgen.h

[matthew green]

   You really have a port that has > 128 operands?

for a short while, i had 130, but i am currently at about 110.
derived operands are ... explosive.

   How about let's make CGEN_SYNTAX_TYPE be an unsigned short for all ports.

for now, unsigned char does still work.  these changes make it so
that if we do need to increase the size, it is as simple as doing
s/char/short/ in cgen.h.