Add VCS and Xcelium run time. Fix RTL for VCS to work correctly

test-vcs/__build.sh

@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+set -e
+
+. ../scripts/sim_vars.sh
+
+rm -rf csrc simv.daidir simv
+
+vcs -full64 -lca -sverilog -notice -nc -timescale=1ns/1ps -f $FFILE -pvalue+top.CPU_COUNT=$CPU_COUNT -l build.log top.sv