We don't support older versions of MSVC at this point, so the version check seems unnecessary.

If we need to alias these within the CPython sources for non-MSVC compilers, then we should do it in source files. In general, we never want to pollute the user's namespace with aliases like this - when we do, it should get a "_Py_" prefix and ideally be behind one of the Py_BUILD_CORE variables.

So I'd rather see a change to remove those definitions from the header files and put them closer to where they belong. If that's too many places, they can go into an internal header with "_Py_" prefix and update all uses.