It's cool that you guys are discussing semantics of who said what and how, but that still doesn't fix this very simple issue that breaks compiling for everyone on Windows who uses MinGW.
-mno-cygwin, was, as far as I know, only ever required to build from cygwin as host to mingw as target.
It is very unlikely that anyone who'd upgrade python still needs this option and is running a gcc cygwin 3.x version. And if it breaks for them it's still better than the current state, which is "broken for everyone else".

Sorry if this sounds snarky, but the fact that this issue has been open for almost 2 years is quite ridiculous.