emit "null" instead of "undefined" for "null" (seems to be faster looking at SunSpider)
emit "null" instead of "undefined" for "null" (seems to be faster looking at SunSpider)

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