Summary

Given:

if True:
    if True:
        pass
    else:
        pass
        # a

        # b
        # c

else:
    pass

We want to preserve the newline after the # c (before the else). However, the last_node ends at the pass, and the comments are trailing comments on the pass, not trailing comments on the last_node (the if). As such, when counting the trailing newlines on the outer if, we abort as soon as we see the comment (# a).

This PR changes the logic to skip all comments (even those with newlines between them). This is safe as we know that there are no "leading" comments on the else, so there's no risk of skipping those accidentally.

Closes #7602.

Test Plan

No change in compatibility.

Before:

After: