PC/pyconfig.h: no more needed. fixed in posixmodule.c Python/import.c: my patch was wrong. we should use _mkdir(const char*) on windows. there is deprecated function mkdir(const char*), but it doesn't take mode_t as parameter. so maybe it is unsafe to call with mkdir(dirpath, dirmode) on windows.
Patch for import.c was checked in (#9752), so last piece is just patch for Include/pythread.h. I'll commit this near future. I believe this is not problematic.