Ruby » Ruby master

stringio: binmode sets encoding to ASCII-8BIT

This should match the behavior of IO#binmode as far
as treating content as ASCII-8BIT (binary).

• ext/stringio/stringio.c (strio_binmode): implement to set encoding
• test/stringio/test_stringio.rb (test_binmode): new test
  [ruby-core:72699] [Bug #11945]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53435 b2dd03c8-39d4-4d8f-98ff-823fe69b080e