bpo-41341: Recursive evaluation of ForwardRef in get_type_hints (#21553)

The issue raised by recursive evaluation is infinite recursion with
recursive types. In that case, only the first recursive ForwardRef is
evaluated.

Lib/test/test_typing.py

@@ -2456,6 +2456,12 @@ class ForwardRefTests(BaseTestCase):
         self.assertEqual(get_type_hints(foo, globals(), locals()),
                          {'a': tuple[T]})
 
+    def test_double_forward(self):
+        def foo(a: 'List[\'int\']'):
+            pass
+        self.assertEqual(get_type_hints(foo, globals(), locals()),
+                         {'a': List[int]})
+
     def test_forward_recursion_actually(self):
         def namespace1():
             a = typing.ForwardRef('A')