Work around #2391: sealed => private[tools]

Author: felixmulder

compiler/src/dotty/tools/io/ZipArchive.scala

@@ -68,7 +68,8 @@ abstract class ZipArchive(override val file: JFile) extends AbstractFile with Eq
   def absolute  = unsupported()
 
   /** ''Note:  This library is considered experimental and should not be used unless you know what you are doing.'' */
-  sealed abstract class Entry(path: String) extends VirtualFile(baseName(path), path) {
+  // FIXME: `private[tools]` should be `sealed` once #2391 is fixed
+  private[tools] abstract class Entry(path: String) extends VirtualFile(baseName(path), path) {
     // have to keep this name for compat with sbt's compiler-interface
     def getArchive: ZipFile = null
     override def underlyingSource = Some(self)