Some wheels don't use "Purelib", meaning the directory layout of the
wheel needs to be manipulated on installation.
Add partial support for Python's "Binary distribution format" when
Purelib is false, since paths such as `includes` & `scripts` are not
remapped into user accessible locations - they will remain in the
wheels "*.data" directory, these could be supported if it's needed
although it seems like a fairly niche use case.
Ref !135709
Campbell Barton
3d49186a4a