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