Merge pull request #255 from mtasaka/ruby30-fix

Fix test suite for ruby 3.0 change for methods on subclass of Array

Author: korny

test/unit/debug.rb

@@ -24,7 +24,8 @@ def test_creation
     ["   \n", :space],
     ["[]", :method],
     [:end_line, :head],
-  ].flatten
+  ]
+  TEST_INPUT.flatten!
   TEST_OUTPUT = <<-'DEBUG'.chomp
 integer(10)operator((\\\))string<content(test)>head[
 

test/unit/statistic.rb

@@ -24,7 +24,8 @@ def test_creation
     ["   \n", :space],
     ["[]", :method],
     [:end_line, :test],
-  ].flatten
+  ]
+  TEST_INPUT.flatten!
   TEST_OUTPUT = <<-'DEBUG'
 
 Code Statistics
@@ -56,4 +57,4 @@ def test_filtering_text_tokens
     assert_equal TEST_OUTPUT, TEST_INPUT.statistic
   end
 
-end
+end