ruby.c: reduce RARRAY_PTR_USE region
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47257 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
ruby.c: reduce RARRAY_PTR_USE region
path to be set before entering the region.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47257 b2dd03c8-39d4-4d8f-98ff-823fe69b080e