delete deprecated IO-like methods

This commit deletes
{IO,ARGF,StringIO,Zib::GZipReader}#{bytes,chars,lines,codepoints}, which
have been deprecated since c47c095b9740e7c19d6fdca29ab661c1089221d4.

Note that String also has those methods.  They are neither depreacted
nor deleted because they are not aliases of counterpart each_something.

1 files changed, 13 insertions, 11 deletions

diff --git a/spec/ruby/library/stringio/lines_spec.rb b/spec/ruby/library/stringio/lines_spec.rb
index d9dd26c2e2..0a2ab0d817 100644
--- a/spec/ruby/library/stringio/lines_spec.rb
+++ b/spec/ruby/library/stringio/lines_spec.rb
@@ -2,18 +2,20 @@ require_relative '../../spec_helper'
 require 'stringio'
 require_relative 'shared/each'
 
-describe "StringIO#lines when passed a separator" do
-  it_behaves_like :stringio_each_separator, :lines
-end
+ruby_version_is ''...'2.8' do
+  describe "StringIO#lines when passed a separator" do
+    it_behaves_like :stringio_each_separator, :lines
+  end
 
-describe "StringIO#lines when passed no arguments" do
-  it_behaves_like :stringio_each_no_arguments, :lines
-end
+  describe "StringIO#lines when passed no arguments" do
+    it_behaves_like :stringio_each_no_arguments, :lines
+  end
 
-describe "StringIO#lines when self is not readable" do
-  it_behaves_like :stringio_each_not_readable, :lines
-end
+  describe "StringIO#lines when self is not readable" do
+    it_behaves_like :stringio_each_not_readable, :lines
+  end
 
-describe "StringIO#lines when passed chomp" do
-  it_behaves_like :stringio_each_chomp, :lines
+  describe "StringIO#lines when passed chomp" do
+    it_behaves_like :stringio_each_chomp, :lines
+  end
 end