add test for throwing an empty Error / catching variant only
add test for throwing an empty Error / catching variant only

dj31416/JSX,jsx/JSX,mattn/JSX,dj31416/JSX,dj31416/JSX,dj31416/JSX,mattn/JSX,jsx/JSX,jsx/JSX,dj31416/JSX,jsx/JSX,jsx/JSX