thread_win32.c: no GVL for interrupt_event

	* thread_win32.c (w32_wait_events): do not acquire GVL, to fix
	  deadlock at read/close race condition.  instead, just ignore
	  interrupt_event if it is closed.
	thread_win32.c: fix index

	* thread_win32.c (w32_wait_events): fix wait object index in the
	  case of interrupt_event is not usable.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@58623 b2dd03c8-39d4-4d8f-98ff-823fe69b080e