CLJS-2581: Create a cljs.repl/*repl-env* dynamic var and bind it around cljs repl loops

Author: Bruce Hauman

src/main/clojure/cljs/cli.clj

@@ -263,7 +263,8 @@ present"
                      (merge copts opts)))]
       (binding [ana/*cljs-ns*    'cljs.user
                 repl/*repl-opts* opts
-                ana/*verbose*    (:verbose opts)]
+                ana/*verbose*    (:verbose opts)
+                repl/*repl-env* renv]
         (when ana/*verbose*
           (util/debug-prn "Compiler options:" (pr-str repl/*repl-opts*)))
         (comp/with-core-cljs repl/*repl-opts*

src/main/clojure/cljs/core/server.clj

@@ -79,7 +79,8 @@
           (with-bindings
             (binding [*in*  (or stdin in-reader)
                       *out* (PrintWriter-on #(out-fn {:tag :out :val %1}) nil)
-                      *err* (PrintWriter-on #(out-fn {:tag :err :val %1}) nil)]
+                      *err* (PrintWriter-on #(out-fn {:tag :err :val %1}) nil)
+                      repl/*repl-env* repl-env]
               (let [opts (merge opts (:merge-opts (repl/setup repl-env opts)))]
                 (binding [repl/*repl-opts* opts]
                   (repl/evaluate-form repl-env env "<cljs repl>"

src/main/clojure/cljs/repl.cljc

@@ -35,6 +35,7 @@
 
 (def ^:dynamic *cljs-verbose* false)
 (def ^:dynamic *repl-opts* nil)
+(def ^:dynamic *repl-env* nil)
 
 (def known-repl-opts
   "Set of all known REPL options."
@@ -856,7 +857,8 @@
     (env/with-compiler-env (or compiler-env (env/default-compiler-env opts))
      (when (:source-map opts)
        (.start (Thread. (bound-fn [] (read-source-map "cljs/core.aot.js")))))
-     (binding [ana/*unchecked-if* false
+     (binding [*repl-env* repl-env
+               ana/*unchecked-if* false
                ana/*unchecked-arrays* false
                *err* (if bind-err
                        (cond-> *out*