Modernize dlopen interface code for FreeBSD and OpenBSD.

Tom Lane <tgl@sss.pgh.pa.us>

Commit: d5b9c9f7335d87dfa3adf171e7a00c8c6cd9b62f
Author: Tom Lane <tgl@sss.pgh.pa.us>
Date: 2011-04-07T19:14:51Z
Releases: 8.4.8
Modernize dlopen interface code for FreeBSD and OpenBSD.

Remove the hard-wired assumption that __mips__ (and only __mips__) lacks
dlopen in FreeBSD and OpenBSD.  This assumption is outdated at least for
OpenBSD, as per report from an anonymous 9.1 tester.  We can perfectly well
use HAVE_DLOPEN instead to decide which code to use.

Some other cosmetic adjustments to make freebsd.c, netbsd.c, and openbsd.c
exactly alike.

Files