bpo-42246: Make sure that f_lasti, and thus f_lineno, is set correctly after raising or reraising an exception (GH-23803)

* Ensure that f_lasti is set correctly after an exception is raised to conform to PEP 626.

* Update importlib

* Add NEWS.

Lib/test/test_exceptions.py

@@ -1488,5 +1488,88 @@ class ImportErrorTests(unittest.TestCase):
                 self.assertEqual(exc.path, orig.path)
 
 
+class PEP626Tests(unittest.TestCase):
+
+    def lineno_after_raise(self, f, line):
+        try:
+            f()
+        except Exception as ex:
+            t = ex.__traceback__
+            while t.tb_next:
+                t = t.tb_next
+            frame = t.tb_frame
+            self.assertEqual(frame.f_lineno-frame.f_code.co_firstlineno, line)
+
+    def test_lineno_after_raise_simple(self):
+        def simple():
+            1/0
+            pass
+        self.lineno_after_raise(simple, 1)
+
+    def test_lineno_after_raise_in_except(self):
+        def in_except():
+            try:
+                1/0
+            except:
+                1/0
+                pass
+        self.lineno_after_raise(in_except, 4)
+
+    def test_lineno_after_other_except(self):
+        def other_except():
+            try:
+                1/0
+            except TypeError as ex:
+                pass
+        self.lineno_after_raise(other_except, 3)
+
+    def test_lineno_in_named_except(self):
+        def in_named_except():
+            try:
+                1/0
+            except Exception as ex:
+                1/0
+                pass
+        self.lineno_after_raise(in_named_except, 4)
+
+    def test_lineno_in_try(self):
+        def in_try():
+            try:
+                1/0
+            finally:
+                pass
+        self.lineno_after_raise(in_try, 4)
+
+    def test_lineno_in_finally_normal(self):
+        def in_finally_normal():
+            try:
+                pass
+            finally:
+                1/0
+                pass
+        self.lineno_after_raise(in_finally_normal, 4)
+
+    def test_lineno_in_finally_except(self):
+        def in_finally_except():
+            try:
+                1/0
+            finally:
+                1/0
+                pass
+        self.lineno_after_raise(in_finally_except, 4)
+
+    def test_lineno_after_with(self):
+        class Noop:
+            def __enter__(self):
+                return self
+            def __exit__(self, *args):
+                pass
+        def after_with():
+            with Noop():
+                1/0
+                pass
+        self.lineno_after_raise(after_with, 2)
+
+
 if __name__ == '__main__':
     unittest.main()