Suppressing special instructions for exceptions

Created by: silabs-oysteink

Currently the ID stage may signal special instructions even though the instruction from IF had a fetch exception (PMA/bus_error). This is because the instruction word is not invalidated in such cases. This change suppresses the *_insn bits in case of exceptions and trigger match. (Trigger match shall not execute because of timing==0, and should thus be ok).

Not SEC clean