This emitter prints out pseudo-machine instructions, instead of the usual
output of the native emitter. It can be enabled on any port via
`MICROPY_EMIT_NATIVE_DEBUG` (make sure other native emitters are disabled)
but the easiest way to use it is with mpy-cross:
$ mpy-cross -march=debug file.py
Signed-off-by: Damien George <damien@micropython.org>
