Function rewind

lib/assets/javascripts/JSXTransformer.js:4096–4101

(token)

    }

    function rewind(token) {
        index = token.range[0];
        lineNumber = token.lineNumber;
        lineStart = token.lineStart;
        lookahead = token;
    }

    function markerCreate() {
        if (!extra.loc && !extra.range) {