Install dynamically loadable modules into a private subdirectory

under libdir, for a cleaner separation in the installation layout
and compatibility with binary packaging standards.  Point backend's
default search location there.  The contrib modules are also
installed in the said location, giving them the benefit of the
default search path as well.  No changes in user interface
nevertheless.

src/test/regress/GNUmakefile

@@ -7,7 +7,7 @@
 #
 #
 # IDENTIFICATION
-#    $Header: /cvsroot/pgsql/src/test/regress/GNUmakefile,v 1.34 2001/04/04 21:15:56 tgl Exp $
+#    $Header: /cvsroot/pgsql/src/test/regress/GNUmakefile,v 1.35 2001/09/16 16:11:11 petere Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -34,6 +34,7 @@ all: pg_regress
 pg_regress: pg_regress.sh GNUmakefile
 	sed -e 's,@bindir@,$(bindir),g' \
 	    -e 's,@libdir@,$(libdir),g' \
+	    -e 's,@pkglibdir@,$(pkglibdir),g' \
 	    -e 's,@datadir@,$(datadir),g' \
 	    -e 's/@VERSION@/$(VERSION)/g' \
 	    -e 's/@host_tuple@/$(host_tuple)/g' \

src/test/regress/pg_regress.sh

@@ -1,5 +1,5 @@
 #! /bin/sh
-# $Header: /cvsroot/pgsql/src/test/regress/Attic/pg_regress.sh,v 1.21 2001/05/27 09:59:30 petere Exp $
+# $Header: /cvsroot/pgsql/src/test/regress/Attic/pg_regress.sh,v 1.22 2001/09/16 16:11:11 petere Exp $
 
 me=`basename $0`
 : ${TMPDIR=/tmp}
@@ -70,6 +70,7 @@ fi
 : ${outputdir=.}
 
 libdir='@libdir@'
+pkglibdir='@pkglibdir@'
 bindir='@bindir@'
 datadir='@datadir@'
 host_platform='@host_tuple@'
@@ -271,6 +272,7 @@ then
 
     bindir=$temp_install/install/$bindir
     libdir=$temp_install/install/$libdir
+    pkglibdir=$temp_install/install/$pkglibdir
     datadir=$temp_install/install/$datadir
     PGDATA=$temp_install/data
 
@@ -450,7 +452,7 @@ fi
 
 if [ "$enable_shared" = yes ]; then
         message "installing PL/pgSQL"
-        "$bindir/createlang" -L "$libdir" $psql_options plpgsql $dbname
+        "$bindir/createlang" -L "$pkglibdir" $psql_options plpgsql $dbname
         if [ $? -ne 0 ] && [ $? -ne 2 ]; then
             echo "$me: createlang failed"
             (exit 2); exit