don't break short C-style comments

[NobbZ]

My editor supports embedding languages in strings and using an annotytion like /* python */ in my nix code preceeding a string I can tell it what language the following string will be in.

Sadly this:

{
  c = /* python */ ''
    if __file__ == '__main__':
      print("hello")
  '';
}

becomes:

{
  c =
    /*
    python
    */
    ''
      if __file__ == '__main__':
        print("hello")
    '';
}

Which keeps the formatting but bloats the code for no reason and makes the comment appear much more important than it is.

Using a single line comment (#) works as well for the editor, though still causes code to move vertically compared to the initial version.

[sellout]

Duplicate of #366.