add helper to convert URLs to Closure SourceFile

Author: dnolen

src/main/clojure/cljs/closure.clj

@@ -116,6 +116,9 @@
 (defmethod js-source-file File [_ ^File source]
   (SourceFile/fromPath (.toPath source) StandardCharsets/UTF_8))
 
+(defmethod js-source-file URL [_ ^URL source]
+  (js-source-file (io/file (.getPath source))))
+
 (defmethod js-source-file BufferedInputStream [^String name ^BufferedInputStream source]
   (SourceFile/fromInputStream name source))