Trailing comma added after comment in call expression

This should be in the same general area of #530:

foo({}
  // Hi
);

foo(
  {}
  // Hi,
);

[heyimalex]

Pretty sure this is the same issue, but with trailing commas enabled:

let example = [
  'FOO',
  'BAR',
  // 'BAZ',
];

let example = [
  "FOO",
  "BAR"
  // 'BAZ',,
];

I noticed when I saw a line that had fifteen trailing commas; on subsequent runs, prettier just keeps adding them 😂

[vjeux]

The reason

var example = [
  "FOO", // example
  "BAR"
];

works is because // example has a special type “line-suffix” with special logic. Otherwise if you join(",", elements) it would put the , after the comment like it happens for the trailing comment here.