* ext/openssl/extconf.rb (CRYPTO_THREADID): check exist or not.

* ext/openssl/ossl.c (ossl_thread_id): use rb_nativethread_self()
  implemented at r42137 to allow threads which doesn't associated with
  Ruby thread to use openssl functions.

* ext/openssl/ossl.c (Init_ossl_locks): If CRYPTO_THREADID is defined
  (OpenSSL 1.0.0 or later has it) use CRYPTO_THREADID_set_callback()
  instead of CRYPTO_set_id_callback() because its argument is
  unsigned long; it may cause id collision on mswin64
  whose sizeof(unsigned long) < sizeof(void*).
  http://www.openssl.org/docs/crypto/threads.html

* ext/openssl/ossl.c (ossl_threadid_func): defined for above.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42141 b2dd03c8-39d4-4d8f-98ff-823fe69b080e