thread_pthread.c: compare with pthread_equal

* thread_pthread.c (ubf_select): compare thread_id with
  pthread_equal() but not directly.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45906 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
thread_pthread.c: timer_thread_pipe struct

* thread_pthread.c (timer_thread_pipe): aggregate timer thread
  pipe stuff into a struct.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45907 b2dd03c8-39d4-4d8f-98ff-823fe69b080e