* ext/openssl/ossl_ssl.c: Correct shutdown behavior w.r.t GC.

* test/openssl/test_ssl.rb: Add tests to verify correct behavior.  

[Bug #8240] Patch provided by Shugo Maeda. Thanks!


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40304 b2dd03c8-39d4-4d8f-98ff-823fe69b080e