Disable installcheck tests for test_session_hooks

The module requires a preloaded library and the defect can't be cured by
a LOAD instruction in the test script. To achieve this we override the
installcheck target in the module's Makefile, and exclude ithe module in
vcregress.pl.

Along the way, revert commit 9989f92aab.

src/tools/msvc/vcregress.pl

@@ -383,6 +383,8 @@ sub modulescheck
 	my $mstat = 0;
 	foreach my $module (glob("*"))
 	{
+		# test_session_hooks can't run installcheck, so skip it here
+		next if $module eq 'test_session_hooks';
 		subdircheck("$topdir/src/test/modules", $module);
 		my $status = $? >> 8;
 		$mstat ||= $status;