StimFrame: Store ringbuff index as member var

Now each StimFrame knows its index within its parent SpMcRingbuff
object.

include/user/spMcRingBuffer.h

@@ -61,7 +61,7 @@ public:
 		{
 			slots[i].~StimulusFrame();  // Destroy default-constructed object
 			new (&slots[i]) StimulusFrame(
-				frameAssemblyDesc->slots[i], callbacks, flags);
+				frameAssemblyDesc->slots[i], callbacks, flags, i);
 		}
 	}
 

include/user/stimulusFrame.h

@@ -77,8 +77,10 @@ public:
 	StimulusFrame(
 		const FrameAssemblyDesc::SlotDesc& slotDesc_,
 		const SmoCallbacks& callbacks,
-		cl_mem_flags flags)
-	: slotDesc(slotDesc_)
+		cl_mem_flags flags,
+		size_t ringBufferIndex_)
+	: slotDesc(slotDesc_),
+	ringBufferIndex(ringBufferIndex_)
 	{
 		if (!callbacks.ComputeManager_createUseHostPtrBuffer)
 		{
@@ -112,6 +114,7 @@ public:
 	SimultaneityStamp simultaneityStamp;
 	FrameAssemblyDesc::SlotDesc slotDesc;
 	std::shared_ptr<smo::compute::ClBuffer> clBuffer;
+	size_t ringBufferIndex;
 };
 
 } // namespace stim_buff