pgsql: Back-patch 7.4 change to show that freebsd 5 and up don't need

Log Message:
-----------
Back-patch 7.4 change to show that freebsd 5 and up don't need
float8-small-is-zero. Per Mark Kirkwood.

Tags:
----
REL7_3_STABLE

Modified Files:
--------------
pgsql/src/test/regress:
resultmap (r1.56.2.4 -> r1.56.2.5)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/resultmap.diff?r1=1.56.2.4&r2=1.56.2.5)