This has been broken since commit af7914c662,
which added the EXPLAIN (TIMING) option. Although that commit included
updates to auto_explain, they evidently weren't tested very carefully,
because the code failed to print node timings even when it should, due to
failure to set es.timing in the ExplainState struct. Reported off-list by
Neelakanth Nadgir of Salesforce.
In passing, clean up the documentation for auto_explain's options a
little bit, including re-ordering them into what seems to me a more
logical order.
898f8a96ef