Put wrappers on all stores of Object pointers into heap Objects.

Also:
Changed ++ loops to [i] loops where I'm touching.
Added some asserts.
Added dvmHeapSourceContainsAddress
Added dvmIsValidObjectAddress

Change-Id: I6586688246064aecabb1e22e1dca276fecee7795
diff --git a/vm/interp/Interp.c b/vm/interp/Interp.c
index dafdbda..da8fa79 100644
--- a/vm/interp/Interp.c
+++ b/vm/interp/Interp.c
@@ -1377,6 +1377,8 @@
         }
     }
 
+    /* Never on the heap, so no write barrier needed. */
+    assert(!dvmIsValidObjectAddress(pResult));
     *pResult = interpState.retval;
 #if defined(WITH_JIT)
     dvmJitCalleeRestore(interpState.calleeSave);