rb_thread_fd_select(). old one is EINTR unsafe.
Patch by Eric Wong. [Bug #5229] [ruby-core:39102]
* test/-ext-/old_thread_select/test_old_thread_select.rb:
a testcase for rb_thread_select().
* ext/-test-/old_thread_select/old_thread_select.c: ditto.
* ext/-test-/old_thread_select/depend: ditto.
* ext/-test-/old_thread_select/extconf.rb: ditto.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@33117 b2dd03c8-39d4-4d8f-98ff-823fe69b080e