thread.c: fix overflow on Windows
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40329 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
thread.c: fix overflow on Windows
timeval.tv_sec is not time_t but mere long.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40329 b2dd03c8-39d4-4d8f-98ff-823fe69b080e