Backport of "build-tools: copy the removed site.py from setuptools" into 1.18
Backport of !655 (merged) "build-tools: copy the removed site.py from setuptools".
Commits:
- 1beeb406 build-tools: copy the removed site.py from setuptools
Backport of !655 (merged) "build-tools: copy the removed site.py from setuptools".
Commits: