bpo-40334: produce specialized errors for invalid del targets (GH-19911)

diff --git a/Lib/test/test_grammar.py b/Lib/test/test_grammar.py
index c24d352..02ba8a8 100644
--- a/Lib/test/test_grammar.py
+++ b/Lib/test/test_grammar.py
@@ -801,6 +801,23 @@
         del abc
         del x, y, (z, xyz)
 
+        x, y, z = "xyz"
+        del x
+        del y,
+        del (z)
+        del ()
+
+        a, b, c, d, e, f, g = "abcdefg"
+        del a, (b, c), (d, (e, f))
+
+        a, b, c, d, e, f, g = "abcdefg"
+        del a, [b, c], (d, [e, f])
+
+        abcd = list("abcd")
+        del abcd[1:2]
+
+        compile("del a, (b[0].c, (d.e, f.g[1:2])), [h.i.j], ()", "<testcase>", "exec")
+
     def test_pass_stmt(self):
         # 'pass'
         pass