InteractiveDriver: use either .tasty or .hasTasty

Author: DarkDimius

compiler/src/dotty/tools/dotc/interactive/InteractiveDriver.scala

@@ -86,11 +86,9 @@ class InteractiveDriver(settings: List[String]) extends Driver {
             else
               null
           prefix != null && {
-            val hasTastyFile = prefix + ".hasTasty"
             binFile match {
               case pf: PlainFile =>
-                val tastyPath = pf.givenPath.parent / hasTastyFile
-                tastyPath.exists
+                List(".hasTasty", ".tasty").map (x => prefix + x) .map(x => pf.givenPath.parent / x ).exists(_.exists)
               case _ =>
                 sys.error(s"Unhandled file type: $binFile [getClass = ${binFile.getClass}]")
             }