Test that blocking on stdout works as expected

[erikcorry]

No description provided.

[floitsch]

LGTM.

[floitsch]

maybe this would make the test faster?

Suggested change

	task::
	// Repeat enough that this pipe will block until the parent reads
	// from stdout.
	1000.repeat:
	out.write "In the beginning the Universe was created.\n"
	out.write "This has made a lot of people very angry and been widely regarded as a bad move.\n"
	stderr.write "Done with stdout."
	// Enough time for the other task to block.
	sleep --ms=1000
	counter := 0
	task::
	// Repeat enough that this pipe will block until the parent reads
	// from stdout.
	1000.repeat:
	out.write "In the beginning the Universe was created.\n"
	out.write "This has made a lot of people very angry and been widely regarded as a bad move.\n"
	counter++
	stderr.write "Done with stdout."
	// Wait for the other task to block.
	last-seen := -1
	while last-seen != counter:
	last-seen = counter
	sleep --ms=50