The purpose of this test is to show a difference in how the TruffleRuby Process#spawn
(and related methods) implement resolving the redirection option values differently than
MRI or JRuby.
MRI and JRuby will call #to_io on the object passed as the value for the redirection
options and TruffleRuby does not.
test_spec.rb tests that Process Spawn tries to convert the value of redirect options like out: and
err: to an IO object before failing.
In this test, an object is passed to Process#spawn that is not an IO object and does not
respond to #fileno but does respond to #to_io.
The test fails if #to_io is not called.
MRI and JRuby call #to_io to get the IO object to use. TruffleRuby does not.