merge revision(s) 39234,39235: [Backport #7843]

	* vm_method.c: call method_removed hook on called class, not on
	  prepending iclass.
	  prepending iclass.  [ruby-core:52207] [Bug #7843]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@39565 b2dd03c8-39d4-4d8f-98ff-823fe69b080e