eatDocComments

fn eatDocComments(p: *Parse) Error!?TokenIndex {
    if (p.eatToken(.doc_comment)) |tok| {
        var first_line = tok;
        if (tok > 0 and tokensOnSameLine(p, tok - 1, tok)) {
            try p.warnMsg(.{
                .tag = .same_line_doc_comment,
                .token = tok,
            });
            first_line = p.eatToken(.doc_comment) orelse return null;
        }
        while (p.eatToken(.doc_comment)) |_| {}
        return first_line;
    }
    return null;
}