hacprsim coredump on using implicit sources

[nbingham1]

export defproc test(bool x) {
prs {
!Vdd -> x-
}
}

test dut;

hacprsim: ../../src/sim/prsim/State-prsim.cc:622: void HAC::SIM::PRSIM::State::__initialize(const bool): Assertion `time_traits::is_zero(current_time)' failed.
Aborted (core dumped)

[fangism]

The issue comes from seeding the event queue with events on !Vdd and !GND.
If they participate in any rules such as tie-up/dns, then the queue needs to be flushed or fast-forwarded with 0 delays, hence the assertion failure.