src/language-html/conditional-comment.js/parseIeConditionalComment
function parseIeConditionalComment(node, parseHtml) {
  if (node.value) {
    let match;
    for (const [regex, parse] of REGEX_PARSE_TUPLES) {
      if ((match = node.value.match(regex))) {
        return parse(node, parseHtml, match);
      }
    }
  }
  return null;
}