Ruby

test_hash.rb: tests for to_h

• test/ruby/test_hash.rb: add tests for Hash#to_h, which copies
  default value/proc but not instance variables.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@54051 b2dd03c8-39d4-4d8f-98ff-823fe69b080e