A few updates here:

* For the specific case of `python -m`, the original argument has been available as `__main__.__spec__.name` since Python 3.4

* Also since Python 3.4, the `multiprocessing` module has correctly handled the -m switch. For more details, see https://docs.python.org/3/whatsnew/3.4.html#multiprocessing and the linked issues.

* However, there are still some cases where it is potentially useful to have access to the full details of how the host Python runtime was invoked, rather than just the arguments that were left after CPython's runtime processing was completed. I filed issue 29857 as a new RFE specifically suggesting a `sys._raw_argv` attribute addressing that question.