Handle field collisions in class merger

Change-Id: Ica3207e70d7860826632ca4af6b29179f3fdda73
diff --git a/src/test/examples/classmerging/MethodCollisionTest.java b/src/test/examples/classmerging/MethodCollisionTest.java
new file mode 100644
index 0000000..a9010a4
--- /dev/null
+++ b/src/test/examples/classmerging/MethodCollisionTest.java
@@ -0,0 +1,57 @@
+// Copyright (c) 2018, 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;
+
+public class MethodCollisionTest {
+
+  public static void main(String[] args) {
+    new B().m();
+    new D().m();
+  }
+
+  public static class A {
+
+    // After class merging, this method will have the same signature as the method B.m,
+    // unless we handle the collision.
+    private A m() {
+      System.out.println("A.m");
+      return null;
+    }
+
+    public void invokeM() {
+      m();
+    }
+  }
+
+  public static class B extends A {
+
+    private B m() {
+      System.out.println("B.m");
+      invokeM();
+      return null;
+    }
+  }
+
+  public static class C {
+
+    // After class merging, this method will have the same signature as the method D.m,
+    // unless we handle the collision.
+    public C m() {
+      System.out.println("C.m");
+      return null;
+    }
+  }
+
+  public static class D extends C {
+
+    public D m() {
+      System.out.println("D.m");
+      super.m();
+      return null;
+    }
+  }
+
+
+}