thread_pthread.c: get_main_stack

* thread_pthread.c (get_main_stack): separate function to get stack of
  main thread.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42730 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
thread_pthread.c: define attr only if used

* thread_pthread.c (native_thread_create): define attr only if it is
  used, and merge pthread_create() calls.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42731 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
thread_pthread.c: fill stack info by creator thread

* thread_pthread.c (native_thread_init_stack): wait the creator thread
  to fill machine stack info, if get_stack_of() is available.
* thread_pthread.c (native_thread_create): fill the created thread
  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
ChangeLog: fix commit miss

* ChangeLog: remove duplicated commit logs.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42733 b2dd03c8-39d4-4d8f-98ff-823fe69b080e