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, 7 insertions, 5 deletions

diff --git a/spec/ruby/core/io/chars_spec.rb b/spec/ruby/core/io/chars_spec.rb
index cd5dbbce4f..2efbdd7333 100644
--- a/spec/ruby/core/io/chars_spec.rb
+++ b/spec/ruby/core/io/chars_spec.rb
@@ -3,10 +3,12 @@ require_relative '../../spec_helper'
 require_relative 'fixtures/classes'
 require_relative 'shared/chars'
 
-describe "IO#chars" do
-  it_behaves_like :io_chars, :chars
-end
+ruby_version_is ''...'2.8' do
+  describe "IO#chars" do
+    it_behaves_like :io_chars, :chars
+  end
 
-describe "IO#chars" do
-  it_behaves_like :io_chars_empty, :chars
+  describe "IO#chars" do
+    it_behaves_like :io_chars_empty, :chars
+  end
 end