Fix issue with freeing allocation with circular references.

Change-Id: I45871c20a192815eafee77f95e17a025f6dcf9d1
diff --git a/rsProgram.h b/rsProgram.h
index 948ba3e..3237a72 100644
--- a/rsProgram.h
+++ b/rsProgram.h
@@ -34,6 +34,7 @@
     Program(Context *, const char * shaderText, uint32_t shaderLength,
                        const uint32_t * params, uint32_t paramLength);
     virtual ~Program();
+    virtual bool freeChildren();
 
     void bindAllocation(Context *, Allocation *, uint32_t slot);