Patch #554716: Use __va_copy where available.
diff --git a/Python/modsupport.c b/Python/modsupport.c
index f4f8298..1f8ef07 100644
--- a/Python/modsupport.c
+++ b/Python/modsupport.c
@@ -418,8 +418,12 @@
 #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)
 		return NULL;