cleanup resolve-type, properly handle non-nullable types

Author: swannodette

src/main/clojure/cljs/compiler.cljc

@@ -495,24 +495,21 @@
     (get mapped-types t) (get mapped-types t)
 
     #?(:clj  (.startsWith t "!")
-       :cljs (gstring/startsWith t "!")) t
+       :cljs (gstring/startsWith t "!"))
+    (str "!" (resolve-type env (subs t 1)))
 
     #?(:clj  (.startsWith t "{")
        :cljs (gstring/startsWith t "{")) t
 
     #?(:clj  (.startsWith t "function")
        :cljs (gstring/startsWith t "function")) t
 
+    #?(:clj  (.endsWith t "=")
+       :cljs (gstring/endsWith t "="))
+    (str (resolve-type env (subs t 0 (dec (count t)))) "=")
+
     :else
-    (let [optional? #?(:clj  (.endsWith t "=")
-                       :cljs (gstring/endsWith t "="))
-          t         (if optional?
-                      (subs t 0 (dec (count t)))
-                      t)
-          ret       (munge (str (:name (ana/resolve-var env (symbol t)))))]
-      (if optional?
-        (str ret "=")
-        ret))))
+    (munge (str (:name (ana/resolve-var env (symbol t)))))))
 
 (defn resolve-types [env ts]
   (let [ts (-> ts string/trim (subs 1 (dec (count ts))))