Formatting: if condition line comments

[helixbass]

There's some instability around trailing if condition comments. Eg this:

if token.comments # `comments` is always an array.
  d

formats like

if token.comments
  # `comments` is always an array.
  d

while if it has an initial indent:

  if token.comments # `comments` is always an array.
    d

it formats like

if (
  token.comments # `comments` is always an array.
)
  d

Probably should always try and print inline (like the first example source) when it fits? Moving into the body (like the first example formatted) seems wrong

[helixbass]

So the discrepancy between the two versions was due to a location data bug in the Coffeescript dependency (updated)

Now (on iss64-if-condition-comment) both format like the second example (where the condition breaks)

(but this also messed with the formatting of tests/comments/if.coffee, see branch diff - needs to get sorted out)

In order to get it to print inline, we'd need to somehow override the fact that Prettier's printTrailingComment() includes a breakParent

Slightly similar to what I ran into in #122, it seems like currently it's sort of all-or-nothing with using Prettier's comment-printing. prettier/prettier#5087 seems to be aimed at changing that

But in the meantime maybe I should look more closely at what those other plugins are doing as workarounds - sounds like they're copy-pasting some of the individual Prettier functions but segregating them eg to their own module

Also, my understanding is that in order to avoid Prettier's own comment-printing kicking in, you have to use willPrintOwnComments(), but would be nice to see if that's the pattern other plugins are using