test_thread.rb: run with default handler

* test/ruby/test_thread.rb (test_thread_timer_and_interrupt): run
  with default handler.

* test/ruby/test_thread.rb (test_thread_{join,value}_in_trap):
  ditto.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45895 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* man/ruby.1: remove deadlink. [ruby-core:62145][Bug #9773]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45896 b2dd03c8-39d4-4d8f-98ff-823fe69b080e