merge revision(s) 33693:
* thread_pthread.c (gvl_yield): don't prevent concurrent sched_yield(). [Bug #5130] [ruby-core:38647]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@34179 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge revision(s) 33693:
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@34179 b2dd03c8-39d4-4d8f-98ff-823fe69b080e