BUG #12885: The result of casting a double to an integer depends on the database version

The following bug has been logged on the website:

Bug reference:      12885
Logged by:          Rich Schaaf
Email address:      rschaaf@commoninf.com
PostgreSQL version: 9.4.1
Operating system:   Windows 7
Description:

The result returned by the following query appears to depend on the
PostgreSQL database version.

The query is:
select column1 AS double_value, cast(column1 AS INT) AS int_value
  from (VALUES (-2.5::double precision),
               (-1.5::double precision),
               (-0.5::double precision),
               (0.5::double precision),
               (1.5::double precision),
               (2.5::double precision)) t;

In PostgreSQL 9.3.5, the query returns:
double_value, int_value
  -2.5, -3
  -1.5, -2
  -0.5, -1
  0.5, 1
  1.5, 2
  2.5, 3

PostgreSQL 9.4.1, the query returns:
  -2.5, -2
  -1.5, -2
  -0.5, 0
  0.5, 0
  1.5, 2
  2.5, 2