BUG #5732: parsing of: "WHERE mycol=123AND ..."

The following bug has been logged online:

Bug reference:      5732
Logged by:          Josh Kupershmidt
Email address:      schmiddy@gmail.com
PostgreSQL version: 8.3 and HEAD
Operating system:   Linux and OS X
Description:        parsing of: "WHERE mycol=123AND ..."
Details:

I noticed that Postgres in many cases will happily tokenize WHERE clauses
having no space between a condition and "AND" or "OR".

For example:
  CREATE TABLE mytab (mycol int);
  INSERT INTO mytab (mycol) VALUES (1), (2);

  SELECT * FROM mytab WHERE mycol = 1AND true;
  SELECT * FROM mytab WHERE mycol = 2OR true;

although some cases produce an error, as I would expect, such as:
  SELECT * FROM mytab WHERE mycol = 2::intOR true;

I think it would be more consistent to raise syntax errors in all these
cases.

Josh