BUG #13489: pg_attribute.attndims turns to 0 when 'create table like/as'

The following bug has been logged on the website:

Bug reference:      13489
Logged by:          sshang
Email address:      sshang@pivotal.io
PostgreSQL version: 9.4.1
Operating system:   centos 6
Description:

When I create a table with array column, the pg_attribute.attndims will set
to a non-zero value. Then I create another table using 'create like' or
'create as', the pg_attribute.attndims of the new table will turn to 0.

postgres=# \d test1;
      Table "public.test1"
 Column |   Type    | Modifiers
--------+-----------+-----------
 id     | integer   |
 datas  | integer[] |
 d2     | integer[] |
 d3     | integer[] |

postgres=# create table test2 (like test1);
CREATE TABLE
postgres=# \d test2;
      Table "public.test2"
 Column |   Type    | Modifiers
--------+-----------+-----------
 id     | integer   |
 datas  | integer[] |
 d2     | integer[] |
 d3     | integer[] |
postgres=# select att.attname, att.attndims from pg_attribute att, pg_class
c where c.relname='test1' and att.attrelid = c.oid;
 attname  | attndims
----------+----------
 tableoid |        0
 cmax     |        0
 xmax     |        0
 cmin     |        0
 xmin     |        0
 ctid     |        0
 id       |        0
 datas    |        1
 d2       |        2
 d3       |        3
postgres=# select att.attname, att.attndims from pg_attribute att, pg_class
c where c.relname='test2' and att.attrelid = c.oid;
 attname  | attndims
----------+----------
 tableoid |        0
 cmax     |        0
 xmax     |        0
 cmin     |        0
 xmin     |        0
 ctid     |        0
 id       |        0
 datas    |        0
 d2       |        0
 d3       |        0
(10 rows)
postgres=# create table test3 as select * from test1;
SELECT 1
postgres=# \d test3;
      Table "public.test3"
 Column |   Type    | Modifiers
--------+-----------+-----------
 id     | integer   |
 datas  | integer[] |
 d2     | integer[] |
 d3     | integer[] |

postgres=# select att.attname, att.attndims from pg_attribute att, pg_class
c where c.relname='test3' and att.attrelid = c.oid;
 attname  | attndims
----------+----------
 tableoid |        0
 cmax     |        0
 xmax     |        0
 cmin     |        0
 xmin     |        0
 ctid     |        0
 id       |        0
 datas    |        0
 d2       |        0
 d3       |        0
(10 rows)