thread_pthread.c: fill stack info by creator thread
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42732 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
thread_pthread.c: fill stack info by creator thread
to fill machine stack info, if get_stack_of() is available.
stack info after starting, if get_stack_of() is available.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42732 b2dd03c8-39d4-4d8f-98ff-823fe69b080e