bpo-36842: Implement PEP 578 (GH-12613)

Adds sys.audit, sys.addaudithook, io.open_code, and associated C APIs.
diff --git a/Doc/library/array.rst b/Doc/library/array.rst
index 4ac7bb5..1f95dd6 100644
--- a/Doc/library/array.rst
+++ b/Doc/library/array.rst
@@ -83,6 +83,7 @@
    to add initial items to the array.  Otherwise, the iterable initializer is
    passed to the :meth:`extend` method.
 
+   .. audit-event:: array.__new__ "typecode initializer"
 
 .. data:: typecodes