MinGW-w64: Initial MinGW(-w64) feature patch.

(by Roumen Petrov and LRN).
diff --git a/Python-2.7.5/Include/objimpl.h b/Python-2.7.5/Include/objimpl.h
index 55e83ec..66a9607 100644
--- a/Python-2.7.5/Include/objimpl.h
+++ b/Python-2.7.5/Include/objimpl.h
@@ -256,6 +256,12 @@
         Py_ssize_t gc_refs;
     } gc;
     long double dummy;  /* force worst-case alignment */
+#if defined(__MINGW32__)
+/* FIXME: what about 64-bit platforms ?
+ * see http://mail.python.org/pipermail/python-dev/2009-July/090724.html
+ */
+	double dummy1;
+#endif
 } PyGC_Head;
 
 extern PyGC_Head *_PyGC_generation0;