Support a delay without a statement in nex_input().
Support a delay without a statement in nex_input().

Add code to check for a plain delay statement (just a delay).
When one is found generate a null statement and do not add it
(the null statement) to result.

CastMi/iverilog,CastMi/iverilog,themperek/iverilog,themperek/iverilog,themperek/iverilog,CastMi/iverilog