Refactored using Method#owner.


	proc.c: super_method of included method

	* proc.c (method_super_method): search the next super method along
	  the included ancestor chain.  [ruby-core:83114] [Bug #13973]

	* vm_method.c (rb_callable_method_entry_without_refinements):
	  return the defined class.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@62865 b2dd03c8-39d4-4d8f-98ff-823fe69b080e