Update the hand-written tests to the latest Chisel

So it appears that Chisel always outputs a "1" in every REG's S
operand.  I don't know or care when that changed, but it appears that
at some point in the past that wasn't true.  As the old operand seems
to be useless, I'm just removing it from all of these tests.
Ensure that REG's S operand is always 1

This is a whole lot like that previous patch for RD nodes: there's an
operand that appears to be defunct and I'm ensuring it has the
expected value because all the backends just ignore it.
Fail with an error message on misformatated operations

I used to not actually check to see if the correct number of operands
were provided for each operand.  This makes a check of that now.