Why exactly are you skeptical? Because it doesn't fix everything in one go? The other changes are also minimal (I'm not even sure if it requires more source changes, maybe I have just to get my #defines right). If you prefer to see a single patch which you can reproduce to fix MinGW compilation completely, I'm willing to do that.

Given that 2.7 is supposed to be a long time support version, I really think people should have a chance to use MinGW. The patch is trivial, but figuring out everything from the compiler error messages can be brain bending.