decode: use correct alu opcode for set control register.

We want to copy operand 1 to the ALU output for setting the control
register.
instructions/types: output alu opcodes.

For use in the simulator when we're implementing instructions.
tests/badaddr: set the exception table and stack.
sim: implement instructions from microcode.

Rather than just interpreting the instructions, use the generated
microcode to take the same steps as the RTL.  This gets us closer to a
real simulation and should make keeping both simulations in sync that
much easier.