merge from trunk (r28440)
* ext/dl/lib/dl/func.rb (call): don't overwrite original arguments to defend from GC. * test/dl/test_func.rb (test_string): add test for above.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_2@28468 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge from trunk (r28440)
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_2@28468 b2dd03c8-39d4-4d8f-98ff-823fe69b080e