Workaround for what is probably a problem in Apple's gcc: <pthread.h> fails

on a function pointer formal argument called "destructor", which is typedeffed
as a different function pointer type in object.h.

Python/thread_pthread.h

@@ -3,7 +3,13 @@
 
 #include <stdlib.h>
 #include <string.h>
+#ifdef __APPLE__
+#define destructor xxdestructor
+#endif
 #include <pthread.h>
+#ifdef __APPLE__
+#undef destructor
+#endif
 #include <signal.h>