id.c, insnhelper.h, insns.def, thread.c, thread_pthread.ci,
  thread_pthread.h, thread_win32.ci, thread_win32.h, vm.h,
  vm_dump.c, vm_evalbody.ci, vm_opts.h: fix comments and
  copyright year.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@13920 b2dd03c8-39d4-4d8f-98ff-823fe69b080e