This tests for a specific interpreter regression where in very
specific circumstances involving remapped functions,
`_setup.sequence_number` is reset, which triggers the "duplicate
O-word label" sanity check.

This test triggers the regression by calling a remap twice.  In the first
call, before the problem O-word, it calls a second-level remap that
returns with a reset `_setup.sequence_number`, so the following O-word
is recorded with an incorrect position.

In the second call, the second-level remap is not invoked, so the
following O-word appears at the correct `_setup.sequence_number`; the
differing positions then triggers the "duplicate O-word label" sanity
check and the program exits with an error.
