Trailing comments are not well assigned

[eemeli]

Describe the bug
Some trailing comments don't get assigned to the best possible node during parsing & composition.

To Reproduce
Un-skip this section of the test suite, and observe the results, in particular for the 1 comments.

Expected behaviour
Either these comments should get assigned the same was as they did with the old parser, or we should have a really good story for why they ought to be handled differently.

Versions (please complete the following information):

• yaml: 2.0.0-4

Additional context
This is tough. The YAML spec says nothing about comments, so the only real yardstick is what "feels right". It's also tricky to handle at the end of a collection, when any number of surrounding collections might also be ending, and you can't tell until the next actual value which all of those ought to even be considered as the place to assign a trailing comment.