CLJS-3418: Some Closure libraries are not lowered because they declare (instead of just ) in deps.js for Google Closure Library (#233)

Co-authored-by: yardwerkz <123331694+yardwerkz@users.noreply.github.com>

Author: swannodette

src/main/clojure/cljs/closure.clj

@@ -236,6 +236,7 @@
 
 (def lang-level
   [:ecmascript3 :ecmascript5 :ecmascript5-strict :ecmascript6 :ecmascript6-strict
+   :ecmascript8
    :ecmascript-2015 :ecmascript-2016 :ecmascript-2017 :ecmascript-2018
    :ecmascript-2019 :ecmascript-2020 :ecmascript-2021 :ecmascript-next
    :no-transpile])
@@ -251,6 +252,7 @@
     :ecmascript5-strict    CompilerOptions$LanguageMode/ECMASCRIPT5_STRICT
     :ecmascript6           CompilerOptions$LanguageMode/ECMASCRIPT_2015 ;; (deprecated and remapped)
     :ecmascript6-strict    CompilerOptions$LanguageMode/ECMASCRIPT_2015 ;; (deprecated and remapped)
+    :ecmasscript8          CompilerOptions$LanguageMode/ECMASCRIPT_2017
     :ecmascript-2015       CompilerOptions$LanguageMode/ECMASCRIPT_2015
     :ecmascript-2016       CompilerOptions$LanguageMode/ECMASCRIPT_2016
     :ecmascript-2017       CompilerOptions$LanguageMode/ECMASCRIPT_2017