Implement simple class merger.

BUG=

Change-Id: Ib22cf7a7d10797b0ba7ed6ef8fb5aa5fda9aaa60

diff --git a/src/test/examples/classmerging/Outer.java b/src/test/examples/classmerging/Outer.java
new file mode 100644
index 0000000..652f794
--- /dev/null
+++ b/src/test/examples/classmerging/Outer.java
@@ -0,0 +1,26 @@
+// Copyright (c) 2017, the R8 project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+package classmerging;
+
+class Outer {
+
+  /**
+   * This class is package private to trigger the generation of bridge methods
+   * for the visibility change of methods from public subtypes.
+   */
+  class SuperClass {
+
+    public String method() {
+      return "Method in SuperClass.";
+    }
+  }
+
+  public class SubClass extends SuperClass {
+    // Intentionally left empty.
+  }
+
+  public SubClass getInstance() {
+    return new SubClass();
+  }
+}