[3.11] gh-104615: don't make unsafe swaps in apply_static_swaps (GH-104620). (#104636)

(cherry picked from commit 0589c6a4d3)

Lib/test/test_compile.py

@@ -1064,6 +1064,24 @@ if 1:
                 with self.subTest(source):
                     self.assertEqual(actual_positions, expected_positions)
 
+    def test_apply_static_swaps(self):
+        def f(x, y):
+            a, a = x, y
+            return a
+        self.assertEqual(f("x", "y"), "y")
+
+    def test_apply_static_swaps_2(self):
+        def f(x, y, z):
+            a, b, a = x, y, z
+            return a
+        self.assertEqual(f("x", "y", "z"), "z")
+
+    def test_apply_static_swaps_3(self):
+        def f(x, y, z):
+            a, a, b = x, y, z
+            return a
+        self.assertEqual(f("x", "y", "z"), "y")
+
 
 @requires_debug_ranges()
 class TestSourcePositions(unittest.TestCase):