Revert "EXPERIMENT: Use UsesLivePrio also with HasDistToTop."

This reverts commit 2e545a3.

Author: JonPsson1

llvm/lib/Target/SystemZ/SystemZMachineScheduler.cpp

@@ -291,7 +291,8 @@ int SystemZPreRASchedStrategy::computeSULivenessScore(
   // already live it should not be a problem to increase the scheduled
   // latency given the OOO execution.
   // TODO: Try scheduling small (DFSResult) subtrees as a unit.
-  bool SchedLow = IsLoad && UsesLivePrio && (PreservesSchedLat || HasDistToTop);
+  bool SchedLow = IsLoad && ((PreservesSchedLat && UsesLivePrio) ||
+                             (HasDistToTop && UsesLiveAll));
 
   // This handles regions with many chained stores of the same depth at the
   // bottom in the input order (cactus). Push them upwards during scheduling.