intern.h: define rb_enumerator_size_func

* include/ruby/intern.h (rb_enumerator_size_func): define strict
  function declaration for rb_enumeratorize_with_size().


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41656 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
intern.h: rb_enumeratorize_with_size with cast

* include/ruby/intern.h (rb_enumeratorize_with_size): cast for
  backward compatibility.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41657 b2dd03c8-39d4-4d8f-98ff-823fe69b080e