message: Add sourceFileName passthrough to File node
diff: @@ -64,7 +64,7 @@ exports.parse = function parse(source, options) {
  // comments, wrap the original Program node with a File node.
  var file = program;
  if (file.type === "Program") {
  - var file = b.file(program);
  + var file = b.file(program, options.sourceFileName);
  file.loc = {
  lines: lines,
  indent: 0,
  