BUG #4436: (E'\\' LIKE E'\\') => f

The following bug has been logged online:

Bug reference:      4436
Logged by:          Mathieu Fenniak
Email address:      hjoiiv@mathieu.fenniak.net
PostgreSQL version: 8.3.3
Operating system:   Linux x86-64
Description:        (E'\\' LIKE E'\\') => f
Details:

I noticed that (SELECT E'\\' LIKE E'\\') returns false, where I would expect
it to return true.  I asked on the #postgresql/freenode IRC channel, and
nobody had a good explanation for this return value, suggesting it may be a
minor bug.