ruby.h: OFFT2NUM redefinition

* include/ruby/ruby.h (OFFT2NUM): RUBY_REPLACE_TYPE also defines macro
  to convert int type to VALUE if found.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40673 b2dd03c8-39d4-4d8f-98ff-823fe69b080e