[3.9] bpo-40334: Produce better error messages on invalid targets (GH-20106) (GH-20973)

* bpo-40334: Produce better error messages on invalid targets (GH-20106)

The following error messages get produced:
- `cannot delete ...` for invalid `del` targets
- `... is an illegal 'for' target` for invalid targets in for
  statements
- `... is an illegal 'with' target` for invalid targets in
  with statements

Additionally, a few `cut`s were added in various places before the
invocation of the `invalid_*` rule, in order to speed things
up.

Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
(cherry picked from commit 01ece63d42b830df106948db0aefa6c1ba24416a)
diff --git a/Lib/test/test_exceptions.py b/Lib/test/test_exceptions.py
index 196f31e..0741bb1 100644
--- a/Lib/test/test_exceptions.py
+++ b/Lib/test/test_exceptions.py
@@ -253,7 +253,7 @@
         check('foo(x for x in range(10), 100)', 1, 5)
         check('(yield i) = 2', 1, 1 if support.use_old_parser() else 2)
         check('def f(*):\n  pass', 1, 7 if support.use_old_parser() else 8)
-        check('for 1 in []: pass', 1, 5 if support.use_old_parser() else 7)
+        check('for 1 in []: pass', 1, 5)
 
     @cpython_only
     def testSettingException(self):