Fix paths on windows

Author: nicolasstucki

compiler/src/dotty/tools/dotc/fromtasty/TASTYRun.scala

@@ -23,7 +23,7 @@ class TASTYRun(comp: Compiler, ictx: Context) extends Run(comp, ictx) {
         case "jar" =>
           JarArchive.open(Path(file.path), create = false).allFileNames()
             .map(_.stripPrefix("/")) // change paths from absolute to relative
-            .filter(e => Path.extension(e) == "tasty" && !fromTastyIgnoreList(e))
+            .filter(e => Path.extension(e) == "tasty" && !fromTastyIgnoreList(e.replace("/", File.separator)))
             .map(e => e.stripSuffix(".tasty").replace("/", "."))
             .toList
         case "tasty" => TastyFileUtil.getClassName(file)