The native emitter will not release/bounce the GIL when running code, so
if it runs tight loops then no other threads get a chance to run (if the
GIL is enabled). So for the thread tests, explicitly include a call to
`time.sleep(0)` (or equivalent) to bounce the GIL and give other threads a
chance to run.
For some tests (eg `thread_coop.py`) the whole point of the test is to test
that the GIL is correctly bounced. So for those cases force the use of the
bytecode emitter for the busy functions.
Signed-off-by: Damien George <damien@micropython.org>
This adds the Python files in the tests/ directory to be formatted with
./tools/codeformat.py. The basics/ subdirectory is excluded for now so we
aren't changing too much at once.
In a few places `# fmt: off`/`# fmt: on` was used where the code had
special formatting for readability or where the test was actually testing
the specific formatting.
