Issue #8847: Disable COMDAT folding in Windows PGO builds.

Analysis by Victor Stinner. Patch by Stefan Krah.

Lib/test/test_list.py

@@ -70,6 +70,14 @@ class ListTest(list_tests.CommonTest):
         check(1000000)
 
 
+    def test_no_comdat_folding(self):
+        # Issue 8847: In the PGO build, the MSVC linker's COMDAT folding
+        # optimization causes failures in code that relies on distinct
+        # function addresses.
+        class L(list): pass
+        with self.assertRaises(TypeError):
+            (3,) + L([1,2])
+
 def test_main(verbose=None):
     support.run_unittest(ListTest)