The rule supports both old and new API;
however, for switching the implementations, I had to use code generation - copying the actual implementations for different API variants into a generated repository.
I did not invent any other mechanics to deal with non existing top level symbols like CcInfo or CcCompilationInfo.
Design document about the new API: https://github.com/bazelbuild/proposals, Partial C++ Starlark API
Introduced in the commit: eb139371c9
* Allow execution on Windows, use utils_win.sh, copy instead of symlink
* Prepare for execution on Windows: set up environment, convert path
also rename TMPDIR since it can clash with widely used variable
