Is Cairo::Surface::Type::WIN32 a problem for Windows programmers?

@fanc999 Is this something you want to comment on?

I happened to find a conversation on a mailing list that I very rarely follow. It begins at https://lists.cairographics.org/archives/cairo/2021-January/029173.html. It's said that WIN32 can be a preprocessor macro, and that the enum Cairo::Surface::Type::WIN32 is then a serious problem.

This concerns only the master branch. I suppose this was never a problem for you, when you built cairomm with MSVC. Do you think it's something that should be fixed? The opinions differ in the thread on the mailing list.

It had been easy to rename Surface::Type::WIN32 before cairomm-1.16 became stable. Now we should avoid breaking API, if possible.