BUG #9606: pg_class relhaspkey column not updated on removal of primary key

The following bug has been logged on the website:

Bug reference:      9606
Logged by:          Jeff Frost
Email address:      jeff@pgexperts.com
PostgreSQL version: 9.2.7
Operating system:   Linux
Description:

pkey_test=# show server_version;
 server_version
----------------
 9.2.7
(1 row)

pkey_test=# create table foo ( bar serial primary key);
NOTICE:  CREATE TABLE will create implicit sequence "foo_bar_seq" for serial
column "foo.bar"
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "foo_pkey"
for table "foo"
CREATE TABLE

pkey_test=# select relname, relhaspkey FROM pg_class where relname = 'foo';
 relname | relhaspkey
---------+------------
 foo     | t
(1 row)

pkey_test=# alter table foo drop constraint foo_pkey;
ALTER TABLE

pkey_test=# select relname, relhaspkey FROM pg_class where relname = 'foo';
 relname | relhaspkey
---------+------------
 foo     | t
(1 row)