Fix test runner not to throw an exception if None is passed for expected registers (don't care) and a test fails
Fix test runner not to throw an exception if None is passed for expected registers (don't care) and a test fails

jbush001/NyuziProcessor,jbush001/NyuziProcessor,FulcronZ/NyuziProcessor,jbush001/NyuziProcessor,jbush001/NyuziProcessor,hoangt/NyuziProcessor,FulcronZ/NyuziProcessor,jbush001/NyuziProcessor,FulcronZ/NyuziProcessor,hoangt/NyuziProcessor,hoangt/NyuziProcessor,hoangt/NyuziProcessor,FulcronZ/NyuziProcessor,jbush001/NyuziProcessor