Async: Drop-in SyncCancelerForAsyncWork without execUncancelableSegment*

We're doing this to prep for the coro port

stimBuffApis/livoxGen1/pcloudStimulusProducer.cpp

@@ -464,8 +464,10 @@ public:
 	void produceFrameReq1_doAssemble_posted(
 		std::shared_ptr<ProduceFrameReq> context)
 	{
-		sscl::SpinLock::Guard lock(pcloudProducer.shouldContinueLock);
-		if (!pcloudProducer.shouldContinue)
+		sscl::SpinLock::Guard guard(
+			pcloudProducer.stimulusProducerCanceler.s.lock);
+		if (pcloudProducer.stimulusProducerCanceler
+			.isCancellationRequestedUnlocked())
 		{
 			callOriginalCallback();
 			return;
@@ -482,8 +484,10 @@ public:
 		std::shared_ptr<ProduceFrameReq> context,
 		bool success, sscl::AsynchronousLoop loop)
 	{
-		sscl::SpinLock::Guard lock(pcloudProducer.shouldContinueLock);
-		if (!pcloudProducer.shouldContinue)
+		sscl::SpinLock::Guard guard(
+			pcloudProducer.stimulusProducerCanceler.s.lock);
+		if (pcloudProducer.stimulusProducerCanceler
+			.isCancellationRequestedUnlocked())
 		{
 			callOriginalCallback();
 			return;
@@ -615,8 +619,10 @@ public:
 			context->darkAmbienceStimFrame->get().lock.writeRelease();
 		}
 
-		sscl::SpinLock::Guard lock(pcloudProducer.shouldContinueLock);
-		if (!pcloudProducer.shouldContinue)
+		sscl::SpinLock::Guard guard(
+			pcloudProducer.stimulusProducerCanceler.s.lock);
+		if (pcloudProducer.stimulusProducerCanceler
+			.isCancellationRequestedUnlocked())
 		{
 			callOriginalCallback();
 			return;
@@ -626,7 +632,7 @@ public:
 			std::cerr << __func__ << ": Failed to compact and collate frame" << std::endl;
 		} else
 		{
-			lock.unlockPrematurely();
+			guard.unlockPrematurely();
 			if (pcloudProducer.pcloudFrameDumper.isEnabled())
 			{
 				try
@@ -748,7 +754,7 @@ void PcloudStimulusProducer::produceFrameReq(
 	sscl::cps::Callback<produceFrameReqCbFn> callback)
 {
 	/**	EXPLANATION:
-	 * We shouldn't acquire the StimulusProducer::shouldContinueLock here because
+	 * We shouldn't acquire stimulusProducerCanceler.s.lock here because
 	 * this function is called from
 	 * StimulusProducer::stimFrameProductionTimesliceInd(), which is already
 	 * holding the lock.