[ruby/psych] Use assert_same in tests where applicable

https://github.com/ruby/psych/commit/0dc25a9d6a

test/psych/test_object_references.rb

@@ -39,7 +39,7 @@ module Psych
       rescue Psych::DisallowedClass
         data = Psych.unsafe_load yml
       end
-      assert_equal data.first.object_id, data.last.object_id
+      assert_same data.first, data.last
     end
 
     def test_float_references
@@ -49,7 +49,7 @@ module Psych
 - *name
       eoyml
       assert_equal data.first, data.last
-      assert_equal data.first.object_id, data.last.object_id
+      assert_same data.first, data.last
     end
 
     def test_binary_references
@@ -60,7 +60,7 @@ module Psych
 - *name
       eoyml
       assert_equal data.first, data.last
-      assert_equal data.first.object_id, data.last.object_id
+      assert_same data.first, data.last
     end
 
     def test_regexp_references
@@ -70,7 +70,7 @@ module Psych
 - *name
       eoyml
       assert_equal data.first, data.last
-      assert_equal data.first.object_id, data.last.object_id
+      assert_same data.first, data.last
     end
   end
 end

test/psych/visitors/test_to_ruby.rb

@@ -319,7 +319,7 @@ description:
 
         list = seq.to_ruby
         assert_equal %w{ foo foo }, list
-        assert_equal list[0].object_id, list[1].object_id
+        assert_same list[0], list[1]
       end
 
       def test_mapping_with_str_tag