handle unused variables in unary operations
handle unused variables in unary operations

psieg/babelsberg-js,psieg/babelsberg-js,psieg/babelsberg-js,fniephaus/babelsberg-js,babelsberg/babelsberg-js,babelsberg/babelsberg-js,psieg/babelsberg-js,babelsberg/babelsberg-js,fniephaus/babelsberg-js,fniephaus/babelsberg-js,babelsberg/babelsberg-js,fniephaus/babelsberg-js