tests/basics/builtin_exec: Test various globals/locals args to exec().

tests/basics/builtin_exec.py

@@ -4,3 +4,29 @@ print(foo())
 d = {}
 exec("def bar(): return 84", d)
 print(d["bar"]())
+
+# passing None/dict as args to globals/locals
+foo = 11
+exec('print(foo)')
+exec('print(foo)', None)
+exec('print(foo)', {'foo':3}, None)
+exec('print(foo)', None, {'foo':3})
+exec('print(foo)', None, {'bar':3})
+exec('print(foo)', {'bar':3}, locals())
+
+try:
+    exec('print(foo)', {'bar':3}, None)
+except NameError:
+    print('NameError')
+
+# invalid arg passed to globals
+try:
+    exec('print(1)', 'foo')
+except TypeError:
+    print('TypeError')
+
+# invalid arg passed to locals
+try:
+    exec('print(1)', None, 123)
+except TypeError:
+    print('TypeError')