Clean up tmpdir

Author: nobu

test/irb/test_init.rb

@@ -273,7 +273,7 @@ def setup
       @original_home = ENV["HOME"]
       @original_irbrc = ENV["IRBRC"]
       # To prevent the test from using the user's .irbrc file
-      ENV["HOME"] = Dir.mktmpdir
+      ENV["HOME"] = @home = Dir.mktmpdir
       IRB.instance_variable_set(:@existing_rc_name_generators, nil)
       super
     end
@@ -283,6 +283,7 @@ def teardown
       ENV["IRBRC"] = @original_irbrc
       ENV["HOME"] = @original_home
       File.unlink(@irbrc)
+      Dir.rmdir(@home)
     end
 
     def test_irb_name_converts_non_string_values_to_string