Revert "In the pg_upgrade test suite, don't write to src/test/regress."

This reverts commit bd1592e8570282b1650af6b8eede0016496daecd.  It had
multiple defects.

Discussion: https://postgr.es/m/12717.1558304356@sss.pgh.pa.us

src/bin/pg_upgrade/test.sh

@@ -110,18 +110,6 @@ PGDATA="${BASE_PGDATA}.old"
 export PGDATA
 rm -rf "$BASE_PGDATA" "$PGDATA"
 
-# Send installcheck outputs to a private directory.  This avoids conflict when
-# check-world runs pg_upgrade check concurrently with src/test/regress check.
-# To retrieve interesting files after a run, use pattern tmp_check/*/*.diffs.
-outputdir="$temp_root/regress"
-EXTRA_REGRESS_OPTS="$EXTRA_REGRESS_OPTS --outputdir=$outputdir"
-export EXTRA_REGRESS_OPTS
-rm -rf "$outputdir"
-mkdir "$outputdir"
-mkdir "$outputdir"/sql
-mkdir "$outputdir"/expected
-mkdir "$outputdir"/testtablespace
-
 logdir=`pwd`/log
 rm -rf "$logdir"
 mkdir "$logdir"

src/test/regress/input/largeobject.source

@@ -203,12 +203,12 @@ END;
 
 SELECT lo_export(loid, '@abs_builddir@/results/lotest.txt') FROM lotest_stash_values;
 
-\lo_import '@abs_builddir@/results/lotest.txt'
+\lo_import 'results/lotest.txt'
 
 \set newloid :LASTOID
 
 -- just make sure \lo_export does not barf
-\lo_export :newloid '@abs_builddir@/results/lotest2.txt'
+\lo_export :newloid 'results/lotest2.txt'
 
 -- This is a hack to test that export/import are reversible
 -- This uses knowledge about the inner workings of large object mechanism
@@ -223,7 +223,7 @@ TRUNCATE lotest_stash_values;
 
 \lo_unlink :newloid
 
-\lo_import '@abs_builddir@/results/lotest.txt'
+\lo_import 'results/lotest.txt'
 
 \set newloid_1 :LASTOID
 

src/test/regress/output/largeobject.source

@@ -385,10 +385,10 @@ SELECT lo_export(loid, '@abs_builddir@/results/lotest.txt') FROM lotest_stash_va
          1
 (1 row)
 
-\lo_import '@abs_builddir@/results/lotest.txt'
+\lo_import 'results/lotest.txt'
 \set newloid :LASTOID
 -- just make sure \lo_export does not barf
-\lo_export :newloid '@abs_builddir@/results/lotest2.txt'
+\lo_export :newloid 'results/lotest2.txt'
 -- This is a hack to test that export/import are reversible
 -- This uses knowledge about the inner workings of large object mechanism
 -- which should not be used outside it.  This makes it a HACK
@@ -407,7 +407,7 @@ SELECT lo_unlink(loid) FROM lotest_stash_values;
 
 TRUNCATE lotest_stash_values;
 \lo_unlink :newloid
-\lo_import '@abs_builddir@/results/lotest.txt'
+\lo_import 'results/lotest.txt'
 \set newloid_1 :LASTOID
 SELECT lo_from_bytea(0, lo_get(:newloid_1)) AS newloid_2
 \gset

src/test/regress/output/largeobject_1.source

@@ -385,10 +385,10 @@ SELECT lo_export(loid, '@abs_builddir@/results/lotest.txt') FROM lotest_stash_va
          1
 (1 row)
 
-\lo_import '@abs_builddir@/results/lotest.txt'
+\lo_import 'results/lotest.txt'
 \set newloid :LASTOID
 -- just make sure \lo_export does not barf
-\lo_export :newloid '@abs_builddir@/results/lotest2.txt'
+\lo_export :newloid 'results/lotest2.txt'
 -- This is a hack to test that export/import are reversible
 -- This uses knowledge about the inner workings of large object mechanism
 -- which should not be used outside it.  This makes it a HACK
@@ -407,7 +407,7 @@ SELECT lo_unlink(loid) FROM lotest_stash_values;
 
 TRUNCATE lotest_stash_values;
 \lo_unlink :newloid
-\lo_import '@abs_builddir@/results/lotest.txt'
+\lo_import 'results/lotest.txt'
 \set newloid_1 :LASTOID
 SELECT lo_from_bytea(0, lo_get(:newloid_1)) AS newloid_2
 \gset

src/tools/msvc/vcregress.pl

@@ -102,13 +102,6 @@ exit 0;
 sub installcheck
 {
 	my $schedule = shift || 'serial';
-	installcheck_internal $schedule;
-	return;
-}
-
-sub installcheck_internal
-{
-	my ($schedule, @EXTRA_REGRESS_OPTS) = @_;
 	my @args = (
 		"../../../$Config/pg_regress/pg_regress",
 		"--dlpath=.",
@@ -118,7 +111,6 @@ sub installcheck_internal
 		"--encoding=SQL_ASCII",
 		"--no-locale");
 	push(@args, $maxconn) if $maxconn;
-	push(@args, @EXTRA_REGRESS_OPTS);
 	system(@args);
 	my $status = $? >> 8;
 	exit $status if $status;
@@ -566,14 +558,6 @@ sub upgradecheck
 	$ENV{PATH} = "$bindir;$ENV{PATH}";
 	my $data = "$tmp_root/data";
 	$ENV{PGDATA} = "$data.old";
-	my $outputdir          = "$tmp_root/regress";
-	my @EXTRA_REGRESS_OPTS = ("--outputdir=$outputdir");
-	rmtree("$outputdir");
-	mkdir "$outputdir"                || die $!;
-	mkdir "$outputdir/sql"            || die $!;
-	mkdir "$outputdir/expected"       || die $!;
-	mkdir "$outputdir/testtablespace" || die $!;
-
 	my $logdir = "$topdir/src/bin/pg_upgrade/log";
 	(mkdir $logdir || die $!) unless -d $logdir;
 	print "\nRunning initdb on old cluster\n\n";
@@ -588,7 +572,7 @@ sub upgradecheck
 	generate_db('',       91, 127, '');
 
 	print "\nSetting up data for upgrading\n\n";
-	installcheck_internal('parallel', @EXTRA_REGRESS_OPTS);
+	installcheck('parallel');
 
 	# now we can chdir into the source dir
 	chdir "$topdir/src/bin/pg_upgrade";