Test arg passing for arraycopy.

Change-Id: Id0a6b6043b9604aa3bb077af0ed858be9bfa5407
diff --git a/test/MyClassNatives/MyClassNatives.java b/test/MyClassNatives/MyClassNatives.java
index e296684..885747a1 100644
--- a/test/MyClassNatives/MyClassNatives.java
+++ b/test/MyClassNatives/MyClassNatives.java
@@ -12,4 +12,5 @@
     static native Object fooSIOO(int x, Object y, Object z);
     static native int fooSII(int x, int y);
     static synchronized native Object fooSSIOO(int x, Object y, Object z);
+    static native void arraycopy(Object src, int src_pos, Object dst, int dst_pos, int length);
 }