src/language-js/printer-estree.js/printJsDocComment
function printJsDocComment(comment) {
  const lines = comment.value.split("\n");

  return concat([
    "/*",
    join(
      hardline,
      lines.map(
        (line, index) =>
          (index > 0 ? " " : "") +
          (index < lines.length - 1 ? line.trim() : line.trimLeft())
      )
    ),
    "*/"
  ]);
}