Ruby

• vm_core.h: remove rb_call_info_t::klass because
  rb_callable_method_entry_t has information about defined class.
• vm_insnhelper.c (vm_search_method): don't set ci->klass because
  it is removed.
• vm_insnhelper.c (rb_equal_opt): ditto.
• vm_insnhelper.c (vm_search_superclass): removed because it is too
  simple to write code directly.
• vm_insnhelper.c (vm_defined): don't use vm_search_superclass().
  This fix avoid searching current callable `me' twice.
• vm_insnhelper.c (vm_search_super_method): ditto.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51200 b2dd03c8-39d4-4d8f-98ff-823fe69b080e