Make PG_TEST_USE_UNIX_SOCKETS work for tap tests on windows.

We need to replace windows-style \ path separators with / when putting socket
directories either in postgresql.conf or libpq connection strings, otherwise
they are interpreted as escapes.

Author: Andres Freund <andres@anarazel.de>
Reviewed-By: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Discussion: https://postgr.es/m/4da250a5-4222-1522-f14d-8a72bcf7e38e@enterprisedb.com

Author: anarazel

src/bin/pg_ctl/t/001_start_stop.pl

@@ -35,6 +35,7 @@
 if ($use_unix_sockets)
 {
 	print $conf "listen_addresses = ''\n";
+	$tempdir_short =~ s!\\!/!g if $PostgreSQL::Test::Utils::windows_os;
 	print $conf "unix_socket_directories = '$tempdir_short'\n";
 }
 else

src/test/perl/PostgreSQL/Test/Cluster.pm

@@ -119,7 +119,18 @@ INIT
 	$use_tcp            = !$PostgreSQL::Test::Utils::use_unix_sockets;
 	$test_localhost     = "127.0.0.1";
 	$last_host_assigned = 1;
-	$test_pghost        = $use_tcp ? $test_localhost : PostgreSQL::Test::Utils::tempdir_short;
+	if ($use_tcp)
+	{
+		$test_pghost = $test_localhost;
+	}
+	else
+	{
+		# On windows, replace windows-style \ path separators with / when
+		# putting socket directories either in postgresql.conf or libpq
+		# connection strings, otherwise they are interpreted as escapes.
+		$test_pghost = PostgreSQL::Test::Utils::tempdir_short;
+		$test_pghost =~ s!\\!/!g if $PostgreSQL::Test::Utils::windows_os;
+	}
 	$ENV{PGHOST}        = $test_pghost;
 	$ENV{PGDATABASE}    = 'postgres';