JS: read compiled js modules

compiler/util/src/org/jetbrains/kotlin/utils/LibraryUtils.kt

@@ -28,6 +28,7 @@ import java.util.jar.JarFile
 import java.util.jar.Manifest
 import java.util.zip.ZipFile
 import kotlin.platform.platformStatic
+import org.jetbrains.kotlin.utils.fileUtils.*
 
 public object LibraryUtils {
     private val LOG = Logger.getInstance(javaClass<LibraryUtils>())
@@ -107,6 +108,29 @@ public object LibraryUtils {
         }
     }
 
+    platformStatic
+    public fun readJsFiles(libraries: List<String>): List<String> {
+        val files = arrayListOf<String>()
+        val libs = libraries.map { File(it) }.filter { it.exists() }
+
+        for (lib in libs) {
+            when {
+                lib.isDirectory() ->
+                    traverseDirectoryWithReportingIOException(lib) { (file, path) ->
+                        files.add(FileUtil.loadFile(file))
+                    }
+                FileUtil.isJarOrZip(lib) ->
+                    traverseArchiveWithReportingIOException(lib) { (content, path) ->
+                        files.add(content)
+                    }
+                else ->
+                    throw IllegalArgumentException("Unknown library format (directory or zip expected): $lib")
+            }
+        }
+
+        return files
+    }
+
     private fun processDirectory(dir: File, action: (File, String) -> Unit) {
         FileUtil.processFilesRecursively(dir, object : Processor<File> {
             override fun process(file: File): Boolean {