REPL: properly redirect streams

I observed local test failures when running ReplTests without this.

Author: smarter

compiler/src/dotty/tools/repl/ReplDriver.scala

@@ -164,7 +164,11 @@ class ReplDriver(settings: Array[String],
     try {
       System.setOut(out)
       System.setErr(out)
-      op
+      Console.withOut(out) {
+        Console.withErr(out) {
+          op
+        }
+      }
     }
     finally {
       System.setOut(savedOut)