merge revision(s) 42724: [Backport #8238]

	* vm_insnhelper.c (vm_call_method): a method entry refers the based
	  class/module, so should search superclass from the origin i-class
	  where the entry belongs to, to get rid of infinite loop when zsuper
	  in a prepended class/module.  [ruby-core:54105] [Bug #8238]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@42726 b2dd03c8-39d4-4d8f-98ff-823fe69b080e