Test that scala#2156 is fixed

Author: DarkDimius

tests/run/i2156.scala

@@ -0,0 +1,37 @@
+class Outer {
+
+  case class Inner()
+
+  val inner: Inner = new Inner
+
+  def checkInstance(o: Outer) =
+    o.inner.isInstanceOf[this.Inner]
+
+  def checkPattern1(i: Any) =
+    i match {
+      case _: Inner => true
+      case _ => false
+    }
+
+  def checkPattern2(i: Any) =
+    i match {
+      case Inner() => true
+      case _ => false
+    }
+
+  def checkEquals(o: Outer) =
+    o.inner == inner
+}
+
+object Test {
+
+  def main(args: Array[String]) = {
+    val o1 = new Outer
+    val o2 = new Outer
+    assert(o1.checkInstance(o2)) // ok
+    assert(!o1.checkPattern1(o2.inner)) // ok under scalac, fails for dotc-compiled code
+    assert(!o1.checkPattern2(o2.inner))  // ok under scalac, fails for dotc-compiled code
+    assert(!o1.checkEquals(o2))  // ok under scalac, fails for dotc-compiled code
+  }
+}
+