git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_2@30570 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merges r30499 from trunk into ruby_1_9_2.¶
also uses __syscall if available for *BSD on 64bit architecture.
[ruby-core:34062]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_2@30570 b2dd03c8-39d4-4d8f-98ff-823fe69b080e