Changes for clojure.core/persistent!

yasuto on Fri, 10 Jun 2011
user> (def foo (transient [1 2 3]))
#'user/foo
user> foo
#<TransientVector clojure.lang.PersistentVector$TransientVector@12c9b4d1>
user> (persistent! foo)
[1 2 3]
user> foo
#<TransientVector clojure.lang.PersistentVector$TransientVector@12c9b4d1>
user> (conj! foo 4)
→ ERROR:Transient used after persistent! call
user> (persistent! foo)
→ ERROR: Transient used after persistent! call