rely on chan datafy and alts nil check in main lib

src/main/clojure/clojure/core/async/flow/impl.clj

@@ -26,15 +26,6 @@
 (defn oid [x]
   (symbol (str (-> x class .getSimpleName) "@" (-> x System/identityHashCode Integer/toHexString))))
 
-(defn chan->data
-  [^clojure.core.async.impl.channels.ManyToManyChannel c]
-  (let [b (.buf c)]
-    {:buffer (if (some? b) (oid b) :none)
-     :buffer-count (count b)
-     :put-count (count (.puts c))
-     :take-count (count (.takes c))
-     :closed? (clojure.core.async.impl.protocols/closed? c)}))
-
 (defn exec->data [exec]
   (let [ess (as-> (str exec) ^String es
               (.substring es (inc (.lastIndexOf es "[")) (.lastIndexOf es "]"))
@@ -49,7 +40,6 @@
     clojure.lang.Fn (-> x str symbol)
     ExecutorService (exec->data x)
     clojure.lang.Var (symbol x)
-    clojure.core.async.impl.channels.ManyToManyChannel (chan->data x)
     (datafy/datafy x)))
 
 (defn futurize ^Future [f {:keys [exec]}]
@@ -242,9 +232,8 @@
                 (loop [nstatus nstatus, nstate nstate, msgs (seq msgs)]
                   (if (or (nil? msgs) (= nstatus :exit))
                     [nstatus nstate]
-                    (let [m (if-some [m (first msgs)] m (throw (Exception.  "messages must be non-nil")))
-                          [v c] (async/alts!!
-                                 [control [outc m]]
+                    (let [[v c] (async/alts!!
+                                 [control [outc (first msgs)]]
                                  :priority true)]
                       (if (= c control)
                         (let [nnstatus (handle-command nstatus v)