First attempt at removing some AC_CHECK_LIB(foo, main) calls.

configure.in

 dnl Process this file with autoconf to produce a configure script.
-dnl $PostgreSQL: pgsql/configure.in,v 1.444 2006/02/03 13:53:15 momjian Exp $
+dnl $PostgreSQL: pgsql/configure.in,v 1.445 2006/02/04 00:42:54 petere Exp $
 dnl
 dnl Developers, please strive to achieve this order:
 dnl
@@ -594,15 +594,15 @@ if test "$PORTNAME" != "aix" -a "$PORTNAME" != "alpha"
 then
 	AC_CHECK_LIB(bsd,      main)
 fi
-AC_CHECK_LIB(util,     setproctitle)
-AC_CHECK_LIB(m,        main)
-AC_CHECK_LIB(dl,       main)
+AC_SEARCH_LIBS(setproctitle, util)
+AC_SEARCH_LIBS(pow, m)
+AC_SEARCH_LIBS(dlopen, dl)
 AC_CHECK_LIB(nsl,      main)
-AC_CHECK_LIB(socket,   main)
+AC_SEARCH_LIBS(socket, [socket wsock32])
 AC_CHECK_LIB(ipc,      main)
 AC_CHECK_LIB(IPC,      main)
 AC_CHECK_LIB(lc,       main)
-AC_CHECK_LIB(dld,      main)
+AC_SEARCH_LIBS(shl_load, dld)
 AC_CHECK_LIB(ld,       main)
 AC_CHECK_LIB(compat,   main)
 AC_CHECK_LIB(BSD,      main)
@@ -612,16 +612,11 @@ AC_CHECK_LIB(resolv,   main)
 AC_SEARCH_LIBS(getopt_long, [getopt gnugetopt])
 # QNX:
 AC_CHECK_LIB(unix, main)
-AC_SEARCH_LIBS(crypt,  crypt)
+AC_SEARCH_LIBS(crypt, crypt)
 # Solaris:
 AC_SEARCH_LIBS(fdatasync, [rt posix4])
 # Cygwin:
-AC_CHECK_LIB(cygipc, shmget)
-# WIN32:
-if test "$PORTNAME" = "win32"
-then
-	AC_CHECK_LIB(wsock32, main)
-fi
+AC_SEARCH_LIBS(shmget, cygipc)
 
 if test "$with_readline" = yes; then
   PGAC_CHECK_READLINE