BUG #10498: documented function json_each(jsonb) is missing.

The following bug has been logged on the website:

Bug reference: 10498
Logged by: Matthew Schinckel
Email address: matt(at)schinckel(dot)net
PostgreSQL version: 9.4beta1
Operating system: Mac OS X
Description:

http://www.postgresql.org/docs/9.4/static/functions-json.html#FUNCTIONS-JSON-PROCESSING-TABLE,
row 2 indicates this function should be there. Executing it shows
otherwise.

matt=# SELECT json_each('{"a":1}'::json);
json_each
-----------
(a,1)
(1 row)

matt=# SELECT json_each('{"a":1}'::jsonb);
ERROR: function json_each(jsonb) does not exist
LINE 1: SELECT json_each('{"a":1}'::jsonb);
^
HINT: No function matches the given name and argument types. You might need
to add explicit type casts.