[llvm] [AMDGPU] Optionally Use GCNRPTrackers during scheduling (PR #93090)

[Valery Pykhtin via llvm-commits]

================
@@ -658,6 +747,19 @@ void GCNScheduleDAGMILive::runSchedStages() {
         continue;
       }
 
+      if (GCNTrackers) {
+        GCNDownwardRPTracker *DownwardTracker = S.getDownwardTracker();
+        GCNUpwardRPTracker *UpwardTracker = S.getUpwardTracker();
+        GCNRPTracker::LiveRegSet *RegionLiveIns =
+            &LiveIns[Stage->getRegionIdx()];
+
+        reinterpret_cast<GCNRPTracker *>(DownwardTracker)
----------------
vpykhtin wrote:

Sorry I meant "reset" method, not constructor.  Basically you're leaving the derived object in undefined state.

https://github.com/llvm/llvm-project/pull/93090