Ruby

• win32/win32.c (rb_w32_select): on 1.8, we don't need to poll sockets,
  because our select is never called from multiple threads.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8@24994 b2dd03c8-39d4-4d8f-98ff-823fe69b080e