merge revision(s) 42902:

	vm_method.c: constify

	* vm_method.c (rb_resolve_refined_method): constify.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@43650 b2dd03c8-39d4-4d8f-98ff-823fe69b080e