function postprocess(messages, filename) {
	const blocks = blocksCache.get(filename);

	blocksCache.delete(filename);

	return messages.flatMap((group, i) => {
		const adjust = adjustBlock(blocks[i]);

		return group.map(adjust).filter(excludeUnsatisfiableRules);
	});
}
Transforms generated messages for output.
@param {Array<Message[]>} messages An array containing one array of messages
    for each code block returned from `preprocess`.
@param {string} filename The filename of the file
@returns {Message[]} A flattened array of messages with mapped locations.