Add regression test for ALTER TABLE .. NO INHERIT on typed tables

This test addition has come up as a suggestion by me, while discussing a
patch that manipulates the area of the code related to this command
pattern.

Author: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/CAEoWx2kggo1N2kDH6OSfXHL_5gKg3DqQ0PdNuL4LH4XSTKJ3-g@mail.gmail.com

src/test/regress/expected/typed_table.out

@@ -41,8 +41,10 @@ ERROR:  cannot alter column type of typed table
 LINE 1: ALTER TABLE persons ALTER COLUMN name TYPE varchar;
                                          ^
 CREATE TABLE stuff (id int);
-ALTER TABLE persons INHERIT stuff;
+ALTER TABLE persons INHERIT stuff; -- error
 ERROR:  cannot change inheritance of typed table
+ALTER TABLE persons NO INHERIT stuff; -- error
+ERROR:  relation "stuff" is not a parent of relation "persons"
 CREATE TABLE personsx OF person_type (myname WITH OPTIONS NOT NULL); -- error
 ERROR:  column "myname" does not exist
 CREATE TABLE persons2 OF person_type (

src/test/regress/sql/typed_table.sql

@@ -20,7 +20,8 @@ ALTER TABLE persons DROP COLUMN name;
 ALTER TABLE persons RENAME COLUMN id TO num;
 ALTER TABLE persons ALTER COLUMN name TYPE varchar;
 CREATE TABLE stuff (id int);
-ALTER TABLE persons INHERIT stuff;
+ALTER TABLE persons INHERIT stuff; -- error
+ALTER TABLE persons NO INHERIT stuff; -- error
 
 CREATE TABLE personsx OF person_type (myname WITH OPTIONS NOT NULL); -- error