CLJS-480: reader/*data-readers* bound inconsistently

Stop binding reader/*data-readers* haphazardly. Instead bind it to
cljs.tagged-literals/*cljs-data-readesr* only in cljs.analyzer/forms-seq
and make sure to actually capture its value to avoid lazy-seq issues.

src/clj/cljs/analyzer.clj

@@ -1425,12 +1425,15 @@
 argument, which the reader will use in any emitted errors."
   ([f] (forms-seq f (source-path f)))
   ([f filename]
-     (let [rdr (readers/indexing-push-back-reader (java.io.PushbackReader. (io/reader f)) 1 filename)
+     (let [rdr (readers/indexing-push-back-reader
+                 (java.io.PushbackReader. (io/reader f)) 1 filename)
+           data-readers tags/*cljs-data-readers*
            forms-seq*
            (fn forms-seq* []
              (lazy-seq
               (let [eof-sentinel (Object.)
                     form (binding [*ns* (create-ns *cljs-ns*)
+                                   reader/*data-readers* data-readers
                                    reader/*alias-map*
                                    (apply merge
                                           ((juxt :requires :require-macros)

src/clj/cljs/compiler.clj

@@ -849,7 +849,6 @@
                     ana/*cljs-ns* 'cljs.user
                     ana/*cljs-file* (.getPath ^File src)
                     reader/*alias-map* (or reader/*alias-map* {})
-                    reader/*data-readers* tags/*cljs-data-readers*
                     *source-map-data* (when (:source-map opts)
                                         (atom
                                           {:source-map (sorted-map)

src/clj/cljs/repl.clj

@@ -176,24 +176,23 @@
           (print (str "ClojureScript:" ana/*cljs-ns* "> "))
           (flush)
           (let [form (try
-                       (binding [*data-readers* tags/*cljs-data-readers*]
-                         (if (seq forms)
-                           (first forms)
-                           :cljs/quit))
+                       (if (seq forms)
+                         (first forms)
+                         :cljs/quit)
                        (catch Exception e
                          (println (.getMessage e))
                          read-error))]
             (cond
-             (identical? form read-error) (recur (ana/forms-seq *in* "NO_SOURCE_FILE"))
-
-             (= form :cljs/quit) :quit
-
-             (and (seq? form) (is-special-fn? (first form)))
-             (do (apply (get special-fns (first form)) repl-env (rest form))
-                 (newline)
-                 (recur (rest forms)))
-
-             :else
-             (do (eval-and-print repl-env env form)
-                 (recur (rest forms))))))
+              (identical? form read-error) (recur (ana/forms-seq *in* "NO_SOURCE_FILE"))
+              
+              (= form :cljs/quit) :quit
+
+              (and (seq? form) (is-special-fn? (first form)))
+              (do (apply (get special-fns (first form)) repl-env (rest form))
+                (newline)
+                (recur (rest forms)))
+
+              :else
+              (do (eval-and-print repl-env env form)
+                (recur (rest forms))))))
         (-tear-down repl-env)))))