--
* thread.c (thread_cleanup_func): unlock all locked mutexes even when
  forking.  [ruby-core:22269]
--
* bootstraptest/test_thread.rb: fix for environment where fork is not
  available.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_1@22733 b2dd03c8-39d4-4d8f-98ff-823fe69b080e