Patch #554716: Use __va_copy where available.

Objects/abstract.c

@@ -1792,8 +1792,12 @@ objargs_mktuple(va_list va)
 
 #ifdef VA_LIST_IS_ARRAY
 	memcpy(countva, va, sizeof(va_list));
+#else
+#ifdef __va_copy
+	__va_copy(countva, va);
 #else
 	countva = va;
+#endif
 #endif
 
 	while (((PyObject *)va_arg(countva, PyObject *)) != NULL)

Objects/stringobject.c

@@ -155,8 +155,12 @@ PyString_FromFormatV(const char *format, va_list vargs)
 
 #ifdef VA_LIST_IS_ARRAY
 	memcpy(count, vargs, sizeof(va_list));
+#else
+#ifdef  __va_copy
+	__va_copy(count, vargs);
 #else
 	count = vargs;
+#endif
 #endif
 	/* step 1: figure out how large a buffer we need */
 	for (f = format; *f; f++) {

Python/getargs.c

@@ -60,8 +60,12 @@ PyArg_VaParse(PyObject *args, char *format, va_list va)
 
 #ifdef VA_LIST_IS_ARRAY
 	memcpy(lva, va, sizeof(va_list));
+#else
+#ifdef __va_copy
+	__va_copy(lva, va);
 #else
 	lva = va;
+#endif
 #endif
 
 	return vgetargs1(args, format, &lva, 0);

Python/modsupport.c

@@ -417,8 +417,12 @@ Py_VaBuildValue(char *format, va_list va)
 
 #ifdef VA_LIST_IS_ARRAY
 	memcpy(lva, va, sizeof(va_list));
+#else
+#ifdef __va_copy
+	__va_copy(lva, va);
 #else
 	lva = va;
+#endif
 #endif
 
 	if (n < 0)