Qutex: Deprecate old gridlock trace; add skeleton new trace

We add the skeleton of a correct history tracer for gridlocks. The
previous history tracer made the incorrect assumption that we would
find the foreign sequence's currently desired LockSet inside of the
lockvoker that it has stored inside of Qutex::currOwner.

include/serializedAsynchronousContinuation.h

@@ -116,7 +116,7 @@ public:
 				bool isDeadlock = traceContinuationHistoryForDeadlockOn(
 					firstFailedQutex);
 
-				bool isGridlock = traceContinuationHistoryForGridlockOn(
+				bool isGridlock = heuristicallyTraceContinuationHistoryForGridlockOn(
 					firstFailedQutex);
 
 				if (!isDeadlock && !isGridlock)
@@ -222,8 +222,15 @@ public:
 			{ return isDeadlockLikely(); }
 
 #ifdef CONFIG_ENABLE_DEBUG_LOCKS
+		struct obsolete {
+			bool traceContinuationHistoryForGridlockOn(Qutex &firstFailedQutex);
+		};
+
 		bool traceContinuationHistoryForDeadlockOn(Qutex &firstFailedQutex);
-		bool traceContinuationHistoryForGridlockOn(Qutex &firstFailedQutex);
+		bool heuristicallyTraceContinuationHistoryForGridlockOn(
+			Qutex &firstFailedQutex);
+		bool completelyTraceContinuationHistoryForGridlockOn(
+			Qutex &firstFailedQutex);
 		bool traceContinuationHistoryForDeadlock(void)
 		{
 			for (auto& lockUsageDesc