Fails parsing ON CONFLICT when SELECT inside INSERT

[nene]

The following fails to parse (in all dialects except SQLite):

INSERT INTO foo (a)
SELECT id FROM foo join bar
ON CONFLICT DO NOTHING;

Wrapping select to parenthesis fixes it:

INSERT INTO foo (a)
(SELECT id FROM foo join bar)
ON CONFLICT DO NOTHING;

Or adding some other clause after FROM:

INSERT INTO foo (a)
SELECT id FROM foo join bar WHERE true
ON CONFLICT DO NOTHING;

Or selecting from just single table

INSERT INTO foo (a)
SELECT id FROM foo
ON CONFLICT DO NOTHING;

The problem seems to be that ON CONFLICT gets confused with JOIN ... ON syntax.