src/language-html/print/tag.js/printOpeningTagPrefix
function printOpeningTagPrefix(node, options) {
  return needsToBorrowParentOpeningTagEndMarker(node)
    ? printOpeningTagEndMarker(node.parent)
    : needsToBorrowPrevClosingTagEndMarker(node)
    ? printClosingTagEndMarker(node.prev, options)
    : "";
}