Add Liberty to verilog conversion tests

tests/liberty_verilog/run-test.sh

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+set -e
+
+for x in *.lib; do
+	echo "Testing on $x.."
+	echo "read_liberty -lib $x" > test.ys
+	echo "write_verilog -blackboxes $x.v.tmp" >> test.ys
+	../../yosys -ql ${x%.lib}.log -s test.ys
+	sed '1,2d' $x.v.tmp > $x.v
+	diff $x.v $x.v.ok
+done