* include/ruby/ruby.h (RHASH_SIZE): Add a cast to suppress a
  warning, comparison between signed and unsigned integer
  expressions [-Wsign-compare], on ILP32.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40960 b2dd03c8-39d4-4d8f-98ff-823fe69b080e