PredefEvelClock, in a similar manner as for type checking.

It  does not  work, I  have changed  my mind  to use  a  more general
clocking algorithm based on  unification. I commit that current state
just in case I change my mind again...

equations is not done at all yet). Also, print the clock decorations
(when clk) in the generated file.

and PredefEvalClock.