[3.14] gh-135326: Test support of __index__ in random.getrandbits() (GH-135356) (#135373)

gh-135326: Test support of __index__ in random.getrandbits() (GH-135356)
(cherry picked from commit 5ae669f)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

Author: miss-islington

Lib/test/test_random.py

@@ -14,6 +14,15 @@
 from fractions import Fraction
 from collections import abc, Counter
 
+
+class MyIndex:
+    def __init__(self, value):
+        self.value = value
+
+    def __index__(self):
+        return self.value
+
+
 class TestBasicOps:
     # Superclass with tests common to all generators.
     # Subclasses must arrange for self.gen to retrieve the Random instance
@@ -809,6 +818,9 @@ def test_getrandbits(self):
         self.gen.seed(1234567)
         self.assertEqual(self.gen.getrandbits(100),
                          97904845777343510404718956115)
+        self.gen.seed(1234567)
+        self.assertEqual(self.gen.getrandbits(MyIndex(100)),
+                         97904845777343510404718956115)
 
     def test_getrandbits_2G_bits(self):
         size = 2**31