message: Fix double newline between line comments
diff: @@ -477,8 +477,13 @@ export default class Generator {
  const lines = n.getLinesBetween(node, comment);
  - // BlockComment already has a newline
  - if (lines.length >= 1 && (comment.type !== 'CommentLine' || trailing)) {
  + // Will always have at least one newline
  + if (node.type === 'CommentLine' || comment.type === 'CommentLine' &&
  + !trailing) {
  + lines.shift();
  + }
  +
  + if (lines.length >= 1) {
  this.inferredNewline(lines[0]);
  }
  