bpo-27635: Fix pickle documentation about __new__ not being called. (GH-19269)

Automerge-Triggered-By: @pitrou
(cherry picked from commit 482259d)

Co-authored-by: Furkan Önder <[email protected]>

Author: miss-islington

Doc/library/pickle.rst

@@ -639,9 +639,9 @@ the methods :meth:`__getstate__` and :meth:`__setstate__`.
    At unpickling time, some methods like :meth:`__getattr__`,
    :meth:`__getattribute__`, or :meth:`__setattr__` may be called upon the
    instance.  In case those methods rely on some internal invariant being
-   true, the type should implement :meth:`__getnewargs__` or
-   :meth:`__getnewargs_ex__` to establish such an invariant; otherwise,
-   neither :meth:`__new__` nor :meth:`__init__` will be called.
+   true, the type should implement :meth:`__new__` to establish such an
+   invariant, as :meth:`__init__` is not called when unpickling an
+   instance.
 
 .. index:: pair: copy; protocol
 

Misc/NEWS.d/next/Documentation/2020-04-01-00-27-03.bpo-27635.VwxUty.rst

@@ -0,0 +1,2 @@
+The pickle documentation incorrectly claimed that ``__new__`` isn't called by
+default when unpickling.