Needed to be updated to use build/mpy-cross.
Also fixes some other issues in the Python wrapper:
- Rename find_mpy_cross_binary to _find_mpy_cross_binary
- Fix passing of -march arg.
- Decode stdout from subprocess.
- Print stdout from mpy-cross in __main__.py.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
Rather than invoking mpy-cross directly via system/subprocess in our build
tools and other tools, this provides a Python interface for it.
Based on https://gitlab.com/alelec/mpy_cross (with the intention of
eventually replacing that as the "official" pypi distribution once setup.py
etc are added).
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
