make: alter how we compute compiler flags for setup.py
This is portable between BSD and GNU make. I'm not thrilled with how
it worked out, but it's portable and solves the problem.
# See http://EditorConfig.org for the specification
root = true
[*.py]
indent_size = 4
indent_style = space
trim_trailing_whitespace = true
[*.{c,h}]
indent_size = 8
indent_style = tab
trim_trailing_whitespace = true