Add test case

Author: odersky

tests/run/i8425.check

@@ -0,0 +1,3 @@
+text: 22
+text: 65
+text: 10

tests/run/i8425.scala

@@ -0,0 +1,15 @@
+import java.io.{ OutputStream, PrintStream }
+
+trait T {
+  val text: String
+  val stream = new PrintStream(new OutputStream {
+    def write(b: Int) = Console.println(s"text: $b")
+  }) {
+    override def println(x: Any) = ???
+  }
+}
+
+@main def Test =
+  val t = new T { val text = "hello" }
+  t.stream.write(22)
+  t.stream.println('A')