Support for the clang subsystems on mingw

[whatTheNameIs (NameIsIs)]

Just for my own records, there was this prior topic about this which contains links to further discussions relevant to (and almost like a backstage for) the merge-requests posted above:

Imitate Visual C++ with MinGW or other C++ compilers (for Python packages based on Visual C++)

I was redirected to this forum by a member of github vscode-cpptools. Please refer to the github link https://github.com/microsoft/vscode-cpptools/issues/5695 to see details of the idea and its comments. It is about how to reduce the size of C/C++ compiler that is required by Python packages, take dtaidistance for instance, among many others. It would be good to be able to run them with MinGW instead, or to reduce MSVC strongly in size. There was a workaround until Python 3.4 which might also …