test_gdbm.rb: teardown

* test/gdbm/test_gdbm.rb (teardown): show tmpdir contents if
  failed.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52432 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/gdbm/test_gdbm.rb

@@ -65,6 +65,13 @@ if defined? GDBM
       ObjectSpace.each_object(GDBM) do |obj|
         obj.close unless obj.closed?
       end
+      begin
+        FileUtils.remove_entry_secure @tmpdir
+      rescue
+        system("ls", "-lR", @tmpdir)
+      else
+        return
+      end
       FileUtils.remove_entry_secure @tmpdir
     end